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CARPENTER'S  AND  BUILDER'S 
ASSISTANT, 

AND 

WOOD  WORKER'S 

GUIDE. 

Revised  and  Enlarged 

BY 

LUCIUS  D,  GOULD, 

Architect  and  Practical  Builder. 


NEW  YORK: 

WILLIAM  T.  COMSTOCK, 

Architectural  Designer  and  Publisher, 
23  WARREN  STREET. 
1897. 


Copyright,  1888. 
LUCIUS  D.  GOULD, 


PREFACE. 

The  experience  of  workmen  generally  will  testify  that  books 
have,  as  yet,  furnished  them  but  small  assistance  in  the  theory  and 
art  of  construction.  The  object  of  the  author  in  publishing  this 
work,  is  to  furnish  them  with  rules  for  finding  sections  of  pieces 
placed  in  any  position  ;  for  cutting  every  description  of  joints ; 
for  finding  the  form  of  the  raking  mould  at  any  point  divergent 
from  the  straight  line  ;  for  springing  and  bending  mouldings  ;  for 
mitering  circular  mouldings,  and  planes  oblique  to  the  base  at  any 
angle;  and  an  easy  system  of  building  stairs  and  railing  for  straight 
and  platform  stairs.  And  eight  plates  containing  steel  square 
problems. 

Together  with  these  rules,  the  author  presents  tables  of  the 
weight,  and  cohesive  strength,  of  the  different  materials  used  in 
the  construction  of  buildings,  as  well  as  the  weight  required  to 
crush  said  materials  ;  a  treatise  on  the  adhesion  of  nails,  screws, 
iron  pins  and  glue;  and  a  geometrical  and  mathematical  demonstra- 
tion for  finding  the  circumference,  and  squaring  the  circle. 

There  can  be  but  little  doubt  that  a  work  of  this  kind  is  needed 
by  Architects  and  Builders,  and  especially  by  Carpenters  and 
Wood-workers,  who  are  inexperienced  in  the  different  kinds  of 
labor  which  they  are  called  upon  to  perform. 

It  is  but  due  to  acknowledge  that  we  have  consulted  the  valuable 
works  of  Thomas  Tredgold  for  the  articles  on  the  strength  and 
weight  of  materials  ;  also  Mr.  Nicholson,  of  London,  for  the 
glossary  of  technical  terms. 


CONTENTS. 

I  S  T      OIF1      PLAT  TH'S  J 


PAGE. 


Plate  i   6. 

To  form  an  actagonal  prism  without  instruments  or  tools. 
To  find  the  size  of  a  piece,  to  form  a  six  sided  prism  when  one  of 
the  sides  is  given. 

Plate  2   a 

To  find  the  backing  of  hip  rafters  for  obtuse  and  acute  angled 
buildings. 

To  find  the  length  of  common  rafters. 
Plate  3   io 

To  square  the  circle,  also  the  ellipse. 

To  find  the  mitre  line  of  a  right  angle. 

To  find  the  diagonal  or  mitre  line  for  an  octagonal  prism. 
Plate  4   12 

To  find  the  intersecting  or  mitre  line  for  hexagon  and  three-sided  prism. 

To  find  the  degree  of  elevation  with  the  square. 
Plate  5   14 

To  find  the  mitre  and  butt  joint  of  a  mill  hopper  when  placed  at  450 
elevation. 

To  find  the  mitre  and  butt  joint  of  a  piece  placed  at  any  angle  of 
elevation. 

Plate  6   16 

To  find  the  mitre  and  butt  joint  of  a  piece  oblique  to  the  base  over 
an  acute  angle. 

Plate  7   18 

To  find  the  mitre  and  butt  joint  of  a  piece  placed  oblique  to  the 
base  over  an  obtuse  angle. 
Plate  8   20 

To  find  the  he;ght  of  an  obelisk  with  the  square. 

To  find  the  distance  to  an  inaccessible  object. 

To  find  the  distance  between  two  inaccessible  objects. 

Plate  9 — The  carpenter's  square   22 

Plate  10   24 

To  form  an  ellipse. 

To  draw  a  polygon. 

To  form  a  false  ellipse. 
Plate  11    26 

Timber  foundation  for  a  frame  building. 

Plate  12 — Balloon  frames   28 

Plate  13 — Cutting  and  jointing  timbers   30 

Plate  14 — Framing   32 

Plate  15   34 

Figure  I.  Hip  and  jack  rafters. 

Figure  2,  Circul  r  stairs. 

Figure  3,  Roof  framing  span  40  to  70  feet. 

Plate  16 — Roof  with  internal  angles   36 

Plate  17 — Plan  and  elevation  of  obtuse  and  acute  angled  buildings, 

projection  of  rafters  and  braces   38 


CONTENTS.  5 


PAGE. 

Plate  18 — Mitre -box — octagonal  and  hexagonal  roofs   40 

Plate  19— Spires   42 

Plate  20— Curve  of  sprung  moulding   44 

Plate  21 — Bevels  :  acute  and  obtuse  angles   46 

Plate  22 — Area  of  a  circle  and  contents  of  a  globe   48 

Plate  23 — Brackets   50 

Plate  24 — The  raking  mould   52 

Plate  25 — Rule  for  finding  mitre  lines   54 

Plate  26 — Circular  and  square  pans   56 

Plate  27 — Circular  desk  and  seat   58 

Plate  28 — Angle  of  rafter  for  French  roof   60 

Plate  29  — Mitreing  of  circular  mouldings.   62 

Plate  30 — Sash  and  Door  tools   64 

Plate  31  — Corinthian  truss   66 

Plate  32— Stairs   6S 

Plate  33 — Straight  and  Platform  stairs   70 

Plate  34 — Hand  railing   72 

Plate  35 — Groin  arches       74 

Plate  36 — Squaring  the  circle   76 


TABLES  AND  MISCELLANEOUS  MATTER. 

Table  showing  length  of  brace   7 

Practical  method  of  finding  contents  in  cubic  feet   9 

Superficial  contents   II 

Construction  of  roofs   13 

Roof  coverings   15 

Long  measure     17 

Square  measure   19 

Strength  of  materials     21 

Posts   23 

Weights  of  materials.   25 

Adhesion  of  nails  27  &  29 

Adhesion  of  screws  and  iron  pins  and  length  of  iron  nails   33 

Adhesion  of  glue  35,  37  &  39 

Metric  system  of  weights  and  measures   41  &  43 

Protection  against  rust   43 

Properties  of  various  woods     45 

How  to  measure  grain  bins   45 

Miscellaneous  notes  and  rules  47  &  49 

Terms  used  in  carpentry   •   5 1  to  75 

Valuation  of  plasterers'  work  ,   66 


PROBLEMS. 


PLATE  1. 

STEEL   SQUARE  PROBLEMS. 

The  Carpenter  s  Square  is  an  instrument  in  general  use,, 
and  is  as  important  and  valuable  to  the  workman  as  the 
clock  is  to  the  time-keeper,  or  the  compass  to  the  mariner. 
The  square  consists  of  a  blade  and  tongue,  placed  at  right 
angles  to  each  other.  The  blade  is  two  feet  long;  the 
tongue  twelve  to  sixteen  inches  long,  divided  into  inches 
and  eighths  of  an  inch.  This  and  the  following  plates 
will  demonstrate  a  few  of  the  uses  to  which  the  square 
may  be  applied. 

Figure  i. — Having  a  piece  of  wood  three  (3)  inches 
square ;  wishing  to  form  an  octagonal  prism,  not  having 
any  instruments  or  tools  convenient,  I  bisected  the  sides 
of  the  piece,  and  drew  the  diagonal  lines ;  after  which  I 
removed  a  section  of  the  piece  and  placed  the  bisected 
lines  on  the  diagonal  lines,  and  drew  the  lines  to  form  the 
octagonal  prism  required. 

Having  the  side  of  a  hexagon,  or  six-sided  prism  given  ; 
to  find  the  size  of  the  piece,  and  the  angles  required. 
Draw  A  B,  Fig.  2,  equal  in  length  to  2  of  the  given  sides. 
Place  the  square  on  the  points  A  and  B,  with  the  given 
side  B  C  on  the  tongue;  then  A  B  and  AC  determines  the 
size  of  the  piece,  and  ABC  the  angle  required  to  form  the 
prism.  The  other  sides  are  found  by  the  same  operation 
with  the  square,  or  by  dividing  the  line  A  B  into  four  equal 
parts,  and  from  the  points  drawing  the  diagonal  line  C  G, 
and  the  perpendicular  lines  C  D  and  C  F. 

To  find  the  area  of  the  prism,  multiply  the  length  of  the 
blade  C  A  by  six,  the  number  of  sides  ;  the  product  wiU  be 
the  area  required. 


TABLE 

Showing  the  length  of  brace  when  the  run  is  given, 
also  the  length  of  run  when  the  brace  is  given. 


RUN. 

JjJ\..rYv^JCi. 

r>p  ACE 

RUN. 

2  ft. 

x 

2  ft. 

2.8248 

2  ft. 

1 .4142 

X 

I  4142 

2  ft  2 

in. 

V 

2  ft  z  in 

3.I8I9 

2  ft.  3  in. 

X 

I  ,CQOQ 

2  ft.  6 

in. 

2  ft.  6  in. 

3-5749 

2  ft.  6  in. 

1.7870 
•  /   /  y 

X 

1.7870 

2  ft.  9 

in. 

v 

2  ft.  9  in. 

3-89°3 

2  ft.  9  in. 

1 .04  c;  1 

x 

1.04^  I 

2  ft 

x 

2  ft 

4.2426 

3  ft- 

2.1213 

x 

2. 1 2 13 

2  ft  3 

in. 

V 
y\ 

2  ft  in 

4.5961 

3  ft.  3  in. 

2.2980 

x 

2. 2980 

1  ft.  6 

in. 

x 

3  ft.  6  in. 

4-9497 

3  ft.  6  in. 

2.4748 

x 

2.4748 

2  ft.  0 

in. 

x 

2  ft.  o  in. 

O     w*  y 

5-3r4i 

3  ft.  9  in. 

2  600 

x 

2. 6^70 

4  ft. 

x 

4  ft. 

5.6568 

4  ft. 

2.8784 

x 

2.8784 

4.  ft.  2 

in. 

x 

4  ft  in 

6.0103 

4  ft.  3  in- 

3.oo<i 
0  0 

x 

3.00  s  1 

4  ft.  6 

in. 

x 

4  ft.  6  in. 

6.3639 

4  ft.  6  in. 

^.1810 
0  y 

x 

3. 1810 
0-  y 

4  ft  O 

in. 

x 

4  ft.  9  in 

6.7 162 

4  ft.  9  in. 

2  2^%l 

x 

5  ft 

X 

5  ft- 

7.0705 

3-5357 

X 

3-5357 

5  ft-  3 

in. 

X 

5  ft-  3  in- 

7.4246 

5  ft.  3  in- 

3-7123 

X 

3-7123 

5  ft.  6 

in. 

X 

5  ft.  6  in. 

7.7781 

5  ft.  6  in. 

3.8890 

X 

3.8890 

5  ft-  9 

in. 

X 

5  ft.  9  in. 

8.1317 

5  ft.  9  in. 

4.0658 

X 

4.0658 

6  ft. 

X 

6  ft. 

8.4852 

6  ft. 

4.2426 

X 

4.2426 

6  ft.  3 

in. 

X 

6  ft.  3  in. 

8.8388 

6  ft  3  in 

4.4194 

X 

4.4194 

6  ft.  6 

in. 

X 

6  ft.  6  in. 

9.1923 

6  ft.  6  in. 

4.5961 

X 

4.5961 

6  ft.  9 

in. 

X 

6  ft.  9  in. 

9-5459 

6  ft.  9  in. 

4.7729 

X 

4.7729 

7  ft. 

X 

yft. 

9.9000 

7  ft. 

4.9500 

X 

4.9500 

7  ft.  3 

in. 

X 

7  ft-  3  in. 

10.2412 

7  ft-  3  [«• 

5.1 206 

X 

5. 1206 

7  ft.  6 

in. 

X 

7  ft.  6  in. 

10.8863 

7  ft.  6  in. 

5-4431 

X 

5-443 1 

7  ft.  9 

in. 

X 

7  ft.  9  in. 

10.9181 

7  ft.  9  in. 

5-459o 

X 

5-459o 

8  ft. 

X 

8  ft. 

11. 3132 

8  ft. 

5.6566 

X 

5-6566 

To  reduce  the  decimals  to  inches,  multiply  by  12  for  inches,  the 
product  by  8  for  eighths,  the  eighths  by  2  for  sixteenths.  Example: 

5.6566=5  ft.  7^  in. 
1 2 


7.8792 
8 


7.0336 


.0672 


CARPENTRY. 


PLATE  2. 

Exhibits  the  operation  of  finding  a  section  of  the  hip  rafters 
for  an  obtuse  and  acute-angled  building,  with  the  steel 
square. 

Figure  i. — The  plan  and  elevation  of  an  obtuse  and 
acute-angled  building  ;  also,  the  elevation  of  the  common 
rafters.  Join  F  S  and  G  S,  the  plan  of  the  hip  rafters. 
Draw  A  B  and  C  E  at  right  angles  to  A  C,  the  common 
rafter  ;  join  B  F.  To  find  the  lengths  of  the  hip  rafters  : 
from  the  point  A  as  centre,  with  A  C  as  radius,  describe  an 
arc ;  from  the  point  C,  and  extend  to  the  line  H  J,  join  F 
J  and  G  H,  the  lengths  required. 

To  find  the  backing,  or  section  of  the  hip  rafters  for  the 
obtuse  angle  when  in  position,  place  the  square  on  the 
line  of  the  rafter,  with  the  distance  A  B  on  the  blade,  and 
the  distance  C  D  on  the  tongue  ;  then  the  tongue  gives 
the  angle  required.  To  find  the  section  of  the  hip  rafter 
for  the  acute  angle,  take  the  distance  F  B  on  the  blade, 
and  C  E  on  the  tongue ;  then  the  tongue  gives  the  angle 
to  form  the  section  required. 

To  find  the  section  or  backing  of  a  hip  rafter  for  right- 
angled  buildings,  place  the  square  on  the  line  of  the  rafter, 
with  the  length  on  the  blade  and  the  rise  on  the  tongue  ; 
then  the  tongue  gives  the  angle  required. 

The  angle  to  cut  the  sides  of  the  common  and  jack  raft- 
ers, are  the  same  for  both.  The  angle  to  cut  the  face  of 
the  jack  rafters  are  at  H  and  J.  The  lengths  of  the  jack 
rafters  are  found  by  dividing  the  common  rafter  into  as 
many  parts  as  there  are  jack  rafters  required.  The  hori- 
zontal and  vertical  lines  for  cutting  the  hips  are  shown  by 
the  dotted  lines  drawn  from  G  H  and  F  J. 

To  find  the  length  of  the  common  rafter  A  C,  place  the 
blade  of  the  square  on  the  line  A  D  ;  square  up  twelve 
inches  from  the  point  A  to  the  line  A  C;  then  the  length 
from  the  point  of  intersection  to  the  point  A,  multiplied 
by  the  number  of  feet  in  the  line  A  D,  gives  the  length 
required;  also  the  horizontal  and  vertical  cuts  for  the  ends 
of  the  rafters.  The  same  operation  applies  to  rinding  the 
lengths  and  cuts  of  braces. 


PROBLEMS. 


9 


A  PRACTICAL  METHOD 

OF    FINDING    THE    NUMBER    OF    CUBIC    FEET    AND    INCHES    CONTAINED  IN 
TIMBER  AND    OTHER  MATERIALS. 

If  the  length  be  given  in  feet  and  inches,  and  the  section, 
or  end,  in  inches,  multiply  the  sides  of  the  section  by  each 
other,  and  divide  by  12.  Also  divide  the  length  by  12  ; 
multiply  these  two  dimensions  by  each  other  duodeci- 
mally,  and  the  product  will  be  the  contents  in  cubic  feet 
and  inches. 

Example. — Find  the  number  of  cubic  feet  in  a  piece  of 
timber  28  feet  long,  1 1  inches  wide,  and  3  inches  thick. 

ft. 

in  12)28,  the  length. 


I  the  sides.        Multiply  2.4 
By  2-9 


2)33 


4'8 


2-9  1 -9-0 


6- 5  gives  6  ft.  5  in., 
the  solidity. 

Example  2. — Find  the  cubic  contents  of  4  quarters,  or 
studs,  each  12  feet  6  inches  long,  and  6  inches  wide,  by 
2y2  inches  thick. 

\  the  sides.  I2-6>  £e  Ien§£h-  . 

o     )  4,  the  number  of  pieces. 

12)15  12)50-0 


i*3  Multiply  4-2 

By  i-3 


4*2 
1*2-6 


5-4-6,  gives  5  ft.  4  in.  and 
6  parts,  the  solidity. 


10 


CARPENTRY. 


PLATE  3 

Exhibits  a  practical  demonstration  of  squaring  the  circle  j  and  an 
inscribed  ellipse.  Also,  of  finding  the  intersecting  or  mitre  lines 
for  square  and  octagonal  figures. 

To  determine  the  exact  size  of  a  square,  the  contents  of  which 
shall  equal  the  contents  of  a  circle  in  square  measure,  is  practi- 
cally demonstrated  at  Fig.  i,  which  represents  a  circle,  and  an 
inscribed  ellipse.  To  find  the  side  of  square,  divide  the  radius 
A  B  into  seven  (7)  equal  parts  ;  square  up  from  the  point  3,  cut- 
ting the  arc  A  D  at  S ;  join  C  S,  the  side  of  the  square,  equal  in 
area  to  the  area  of  the  circle.  Describe  the  ellipse  any  size,  cut- 
ting the  line  C  S  at  N  ;  then  C  N  equals  the  sides  of  a  square 
equal  in  area  to  the  area  of  the  inscribed  ellipse.  Place  the  square 
on  the  diameter,  with  the  heel  at  the  point  S,  and  find  the  exact 
size  of  the  square  required. 

To  find  the  intersecting  line  or  mitre,  for  a  right  angle  Fig.  2, 
place  the  square  at  equal  distances  from  the  heel,  then  the  blade 
and  tongue  gives  the  lines  required. 

Fig.  3.  To  find  the  side  of  an  octagonal  prism,  when  the  side 
of  the  square  piece  is  given:  Bisect  the  sides  of  the  piece  ;  place 
the  square  on  the  side  A  B,  with  the  length  bisected  on  the  blade 
and  tongue  ;  then  the  tongue  cuts  the  side  at  the  point  to  gauge 
for  the  piece  to  be  removed  for  the  prism  required.  To  find  the 
size  of  square  required  for  an  octagonal  prism,  when  the  side  is 
given:  Let  C  D  equal  the  given  side;  place  the  square  on  the  line 
of  the  side,  with  one-half  of  the  side  on  the  blade  and  tongue; 
then  the  tongue  cuts  the  line  at  the  point  B,  which  determines  the 
size  of  the  square  and  the  piece  to  be  removed. 

To  find  the  area  of  an  octagonal  prism:  Multiply  the  given 
side  by  eight,  the  number  of  sides  ;  the  product  by  half  of  the 
altitude  of  the  isosceles  triangle  formed  by  the  side  and  diagonal 
lines.    The  product  equals  the  area  required. 

BY  CALCULATION. 

Suppose  I  have  a  lot  of  ground  40  feet  square.  Wanting  to 
know  how  far  to  measure  from  the  angles  to  form  an  octagon: 
40-^-2=20X20=400+400=^800=28.28 — 40=11.72  feet,  the  dis- 
tance required. 

Wanting  to  know  the  size  of  lot  when  the  side  is  given:  Say  20 
feet-4-2=ioXio=ioo+  100=^/200=14.14+20=34. 14+14.14=48.28. 
feet  square,  the  size  required. 


Fig.  2. 


Fig.  3. 


PROBLEMS. 


11 


A  PRACTICAL  METHOD 

Of  finding  the  superficial  contents  of  boards  and  timber. 

For  boards,  multiply  the  width,  in  inches,  by  the  length, 
in  feet,  and  divide  by  12. 

Example. — Find  the  number  of  feet  in  a  board  1  inch 
thick,  9  inches  wide  and  13  feet  long. 

9 

12)117 


9-9=9  feet  9  inches. 
Example  2d. — Find  the  number  of  feet  in  a  piece  of 
timber  3x10  inches,  21  feet  long. 

10  inches  wide. 
3     "  thick. 

12)30 


2*6  inches  in  each  foot  in  length. 
21  feet  long. 

42 
io-6 


52*6  gives  52  feet  6  inches,  the  number 
of  feet  in  the  piece. 


12 


CARPENTRY. 


PLATE  4. 

Having  the  side  of  a  six-sided  prism,  to  find  the  diagonal  or 
mitre  line,  with  the  square. 

Figure  I. — Place  the  square  on  the  side  given,  with  one- 
half  of  the  side  on  the  tongue ;  then  the  tongue  and  the 
side  of  the  hexagon  gives  the  angle  to  cut  for  the  mitre. 

Fig.  2  represents  the  operation  of  finding  the  mitre  for 
an  equilateral  triangle,  by  placing  the  square  on  the  side, 
with  one-half  the  distance  on  the  blade  ;  then  the  tongue 
and  the  sides  give  the  angle  required  to  cut  the  mitre. 

Fig.  3  represents  a  quadrant  of  900,  with  the  steel  square 
placed  equally  distant  from  the  heel,  on  the  tongue  and 
blade,  to  intersect  the  arc  at  45°.  To  find  the  run  to  any 
degree  of  elevation,  slide  the  square  to  and  from  the  centre 
of  quadrant,  for  the  run  and  height  required,  which  will 
be  found  useful  to  workmen  in  finding  the  elevation  of 
roofs,  etc.,  when  specified  in  degrees  by  the  architect 


ROOFS. 


Construction  of  Roofs. 

In  old  Gothic  buildings,  the  roof  always  had  a  high 
pitch,  its  outline  formed  a  striking  feature,  and  in  general 
had  a  graceful  proportion  with  the  magnitude  of  the 
building;  sometimes,  however,  it  presented  a  plain  sur- 
face of  too  great  extent,  as  the  roof  of  Westminster  Hall. 
Though  a  high  roof  is  in  perfect  unison  with  the  aspiring 
and  pyramidal  character  of  Gothic  architecture,  in  the 
more  chaste  and  classic  style  of  the  Greek,  it  is  a  less  con- 
spicuous object.  Many  of  the  Grecian  buildings  were 
never  intended  to  be  roofed  at  all;  but  where  a  roof  is 
necessary,  it  was  not  attempted  to  be  hidden,  but  consti- 
tuted one  of  the  most  ornamental  parts  of  the  building. 
Of  timber  roofs,  we  have  no  examples  in  Grecian  build- 
ings ;  but  the  beautiful  stone  roof  of  the  Octagon  Tower 
of  Andronicus  Cyrrhestes,  and  that  of  the  Choragic  Monu- 
ment of  Lysicrates,  are  sufficient  to  show  that  they  were 
more  inclined  to  ornament  than  to  hide  this  essential  part 
of  a  building. 

The  height  of  roofs,  at  the  present  time,  is  seldom  above 
one-third  of  the  span,  and  should  never  be  less  than  one- 
sixth.  The  most  usual  pitch  is  when  the  height  is  one- 
fourth  of  the  span,  or  when  the  angle  with  the  horizon  is 
26%  degrees. 

The  pediments  of  the  Greek  temples  make  an  angle  of 
from  12  to  16  degrees  with  the  horizon  ;  the  latter  corres- 
ponds nearly  with  one-seventh  of  the  span.  The  pedi- 
ments of  the  Roman  buildings  vary  from  23  to  24  degrees  ; 
24  degrees  is  nearly  two-ninths  of  the  span. 


14 


CARPENTRY. 


PLATE  5 

Exhibits  the  operation  of  finding  the  mitre  and  butt 
joints  for  a  mill  hopper,  when  the  sides  are  placed  at  an  angle 
of  450  /  also  to  find  the  mitre  and  butt  joints  to  a  piece  placed 
at  any  angle  from  a  horizontal  to  a  perpendicular,  with  the 
steel  square. 

Figure  i. — The  elevation  of  a  mill  hopper.  To  find  the 
mitre  for  the  edge  and  sides,  place  the  square  on  the  line 
of  the  edge  and  sides,  with  A  B  on  the  blade  and  A  C  on 
the  tongue  ;  then  the  tongue  gives  the  lines  for  the  face 
and  edge  required.  To  find  the  angle  for  the  butt  joint, 
set  off  from  the  heel  of  the  square  equal  to  A  D  on  the 
blade  and  C  D  on  the  tongue ;  then  the  tongue  gives  the 
line  required. 

Figure  2. — Exhibits  the  section  of  a  piece  placed 
oblique  to  the  base,  to  be  mitred  at  a  right  angle.  To 
find  the  line  to  cut  the  edge,  place  the  square  on  the  line 
A  S,  with  A  C  on  the  blade  and  A  B  on  the  tongue ;  then 
the  tongue  gives  the  line  required.  To  find  the  line  to 
cut  the  side  of  the  piece,  place  the  square  on  the  line  H 
J,  with  A  C  on  the  blade  and  B  C  on  the  tongue ;  then 
the  tongue  gives  the  line  required.  To  find  the  line  to 
cut  the  edge  for  the  butt  joints,  place  the  square  on  the 
line  P  R,  with  E  D  on  the  blade  and  B  D  on  the  tongue ; 
then  the  tongue  gives  the  line  required. 


ROOFING. 


15 


ROOF  COVERINGS. 

The  kinds  of  covering  used  for  timber  roofs,  are  cop- 
per, lead,  iron,  tinned  iron,  slates  of  different  kinds,  tiles, 
shingles,  gravel,  felt  and  cement.  Taking  the  angle  for 
slates  to  be  26y2  degrees,  the  following  table  will  show 
the  degree  of  inclination  that  may  be  given  for  other 
materials. 


Kind  of  covering. 

Inclination  to  the  ho- 
rizon, in  degrees. 

Height  of  roof 
in  parts 
of  the  span. 

Weight  upon  a 
square  of  roofing. 

Deg. 

Min. 

Tin  

3 

5° 

1 

18 

pounds. 

3 

50 

1 

18 

IOO 

u 

3 

50 

1 

18 

700 

it 

22 

OO 

1 

5 

II20 

it 

"  ordinary.... 

26 

33 

1 
1 

9OO 

tt 

"  fine  

26 

33 

i 

500 

u 

29 

4i 

2 
7 

I78o 

4( 

Gravel  

Felt  and  Cement. . . 

Felt  and  Cement  or  Gravel  Roofing  can  be  used  at  almost  any  inclination 
that  other  materials  are  used. 


16 


CARPENTRY. 


PLATE  6. 

Exhibits  the  operation  of  finding  the  lines  for  the  edge  and 
side  of  a  piece  placed  oblique  to  the  base,  to  be  mitred  over  an 
acute  angle. 

At  Figure  i,  draw  the  base  and  perpendicular  indefi- 
nitely ;  place  the  side  of  the  piece  A  B  at  the  angle  re- 
quired ;  draw  A  C  at  right  angles  to  A  B  ;  produce  B  A 
to  D  ;  draw  D  E  parallel  to  C  B  ;  draw  the  plan  of  the 
acute  angle  required.  To  find  the  line  to  cut  the  edge, 
place  the  square  on  the  line,  with  F  G  on  the  tongue  and 
A  C  on  the  blade  ;  then  the  tongue  gives  the  line  required. 
To  find  the  line  to  cut  the  side  A  B,  place  the  square  on 
the  line,  with  F  G  on  the  tongue  and  A  B  on  the  blade ; 
then  the  tongue  gives  the  line  required.  The  angle  to  cut 
the  edge  for  a  butt  joint,  is  shown  at  E  H  A. 


TABLES.  1 1 


LONG  MEASURE. 

Long  measure  is  used  in  measuring  length  or  distance 
only,  without  regard  to  breadth  or  depth.    Its  denomina- 
tions are  leagues,  miles,  furlongs,  rods,  yards,  feet  and  inches* 
12     inches       -  make  i  foot. 

3     feet       -  "i  yard. 

5^  yards,  or  \6%  feet,  -  "     I  rod. 

40     rods      ...       -  "     i  furlong. 

8     furlongs,  or  320  rods,      -        "     1  mile. 
3     miles     -  "     1  league. 

Note. — 4  inches  make  1  hand  ;  9  inches  1  span  ;  18  inches 
1  cubit ;  6  feet  1  fathom  ;  4  rods,  or  100  links,  1  chain  ;  25  links 
1  rod  ;  7S  inches,  1  link. 

The  chain  is  commonly  used  in  measuring  roads  and 
land,  and  is  called  Gunter's  chain,  from  the  name  of  the 
inventor. 

A  knot,  in  sea  phrase,  answers  to  a  nautical  or  geographi- 
cal mile  of  5,280  feet. 

Mariner's  measure  is  a  kind  of  long  measure  used  in  es- 
timating distances  at  sea. 

6  feet  -  make  1  fathom. 

120  fathoms        -  <      1  cable-length. 

880  fathoms,  or  y\  cable,  4      1  mile. 


18 


CARPENTRY. 


PLATE  7 

Exhibits  a  piece  placed  oblique  to  the  base,  to  be  mitred 
over  an  obtuse  angle  with  the  steel  square. 

To  find  the  line  to  cut  the  edge  of  the  piece  A  B, 
Figure  i,  place  the  square  on  the  line,  with  E  D  on  the 
tongue  and  B  C  on  the  blade  ;  then  the  tongue  gives  the 
line  required.  To  find  the  line  to  cut  the  side  A  B, 
place  the  square  on  the  line  with  E  D  on  the  tongue,  and 
A  B  on  the  blade;  then  the  tongue  gives  the  line  required. 
To  find  the  line  to  cut  the  edge  for  a  butt  joint,  place  the 
square  on  the  line,  with  F  H  on  the  tongue,  and  F  G  on 
the  blade;  then  the  tongue  gives  the  line  required. 

Figure  2. — To  find  the  centre  when  an  arc  is  given : 
Draw  two  chord  lines  six  inches  long ;  then  place  the 
blade  of  the  square  three  inches  from  the  heel  on  each  of 
the  chords,  and  at  the  intersection  of  the  tongues  will  be 
found  the  centre  required. 


To  divide  a  piece  into  any  number  of  equal  parts,  place 
the  square  on  the  piece,  with  the  points  on  the  edges  ; 
then  if  4  equal  parts  are  required,  mark  the  piece  from 
the  points  6,  12  and  18.  If  five  pieces  are  required,  place 
the  heel  of  the  square  and  the  figure  20  on  the  edge,  then 
mark  from  the  points  4,  8,  12  and  16.  By  this  rule  the 
piece  can  be  divided  into  any  number  from  2  to  24  equal 
parts  without  the  dividers. 

To  find  the  distance  to  gauge  from  the  angles  of  a 
square  piece  to  form  an  octagonal  prism  :  Place  the  square 
on  the  side  of  the  piece  diagonally  ;  then  gauge  from  the 
points  7  and  17,  the  distance  required. 


TABLES.  19 


SQUARE  MEASURE. 

Square  measure  is  used  in  measuring  surfaces,  or  things  whose 
length  and  breadth  are  considered,  without  regard  to  heighth  or 
depth  :  as  land,  flooring,  plastering,  etc.  Its  denominations  are 
Acres,  Roods,  Square  Rods,  Yards,  Square  feet,  and  Square  iuchts* 

144     square  inches  -          make  i  square  foot 

9     square  feet        -  "  1      "  yard 

30X  square  yards  or  )  «  j  1  scluare  roc** 

272^  square  feet       j  (  perch  or  pole. 

40     square  rods        -  "  1  rood. 

4     roods,  or  160  square  rods       "  1  acre. 

640     acres      -          -  "  1  square  mile. 

Note. — 16  square  rods  make  1  square  chain;  10  square  chains,  or  100,000 
square  links,  make  an  acre.  Flooring,  roofing,  plastering,  etc.,  are  frequently 
estimated  by  the  "square,"  which  contains  100  square  feet. 

Note. — A  chain  is  66  feet  in  length,  and  is  divided  into  100  equal  parts,  or 
links.    The  length  of  a  link  is,  therefore,  7.92  inches. 


20 


CARPENTRY. 


PLATE  8. 

FIGURE  i. — Wishing  to  know  the  height  of  an  obelisk 
situated  on  a  horizontal  plane,  I  measured  70  feet  in  a 
right  line  from  the  centre  of  its  base,  and  raised  a  perpen- 
dicular five  feet  high,  and  placed  the  square  twelve  inches 
from  the  heel,  at  right  angles  to  the  perpendicular ;  then 
with  a  straight  edge  took  the  angle  of  elevation  of  the  top,, 
which  I  found  to  be  8.7  inches  to  the  foot.  Multiplied 
by  70=609—12=50.75+5=55.75  feet,  the  height  required. 

Figure  2. — Wanting  to  know  the  distance  between  two 
inaccessible  objects,  A  and  B,  from  the  point  C,  I  draw 
CA  and  CB  ;  at  right  angles  to  CA  and  CB,  I  measured 
thirty  feet  to  the  points  E  and  S,  where  I  placed  the 
square  ;  then  with  the  straight  edge  took  the  observation, 
and  found  that  12  inches  on  E  C  gave  13.2  inches  on  the 
line  C  AX30=396-J-i2=33  feet  from  C  to  A,  and  by  the 
same  operation  on  the  line  C  S  determines  the  length  of 
C  B  50  feet.  Having  found  the  angle  and  two  sides  of  the 
triangle  C  B  A,  the  other  side  can  be  found  by  drawing 
to  a  scale,  or  by  trigonometry,  where  two  sides  and  the  in- 
cluded angle  being  given,  to  find  the  other  angles  and  side. 

Figure  3. — Being  on  the  side  of  a  river,  and  wanting  to 
know  the  distance  to  a  tree  on  the  other  side,  I  measured 
40  feet  at  right  angles  from  the  tree  and  station  ;  placed 
the  square  at  the  point,  and  found  by  observation  that  the 
square  gave  22.7  inches  to  the  foot,  which  multiplied 
by  40=908^-12=75.75  feet,  the  distance  required. 


TABLES. 


21 


WEIGHT  OR  FORCE 

REQUIRED    TO    TEAR     ASUNDER    ONE    SQUARE     INCH    OF    THE  DIFFERENT 
MATERIALS  USED  IN  THE  CONSTRUCTION  OF  BUILDINGS. 

WOODS  AND  METALS. 


Oak,  American, 

17,300 

Swedish  Iron, 

78,850 

Oak,  English, 

-  19,800 

English  Iron, 

-  55,772 

Beech, 

17,700 

French  Iron,  - 

61,041 

Ash, 

-  16,700 

Russian  Iron, 

-  59,472 

Elm,  - 

13,489 

Cast  Iron, 

42,000 

Walnut,  - 

-  8,130 

Steel,  Soft,  - 

-  120,000 

Norway  Pine, 

14,300 

Ivory, 

16,000 

Georgia  Pine, 

-  7,8i8 

Marble, 

8,700 

White  Pine, 

8,800 

Whalebone, 

7,600 

Iron  Wire,  - 

-  n3,o77 

To  find  the  strength  of  Cohesion :  Multiply  area  of  section,  in 
inches,  by  the  weight  required  to  tear  one  inch  asunder,  and  the 
product  is  the  strength  in  pounds. 


WEIGHTS 


'REQUIRED  TO  CRUSH  ONE  CUBIC  INCH    OF  SEVERAL   MATERIALS  USED    IN  THE 
CONSTRUCTION  OF  BUILDINGS. 


METALS. 


WOODS. 


Cast  Iron, 
Brass, 

Copper,  Cast, 
Lead,  Cast,  - 


Freestone, 
Limestone,  Black, 
Granite,  Blue,  - 


116,700 

154,784 
116,102 
8,042 


Elm, 

American  Pine, 
White  Deal,  - 
White  Oak,  - 

English  Oak,  - 


STONES. 


18,006    Brick,  hard, 
-   19,450    Brick,  soft, 
20,890  Chalk, 


1,284 
1,606 
1,928 
3,24o 
3,860 

i,754 
1,224 
1,040 


,22 


CARPENTRY. 


.    _  PLATE  9. 

Figure  i. — Exhibits  the  use  of  the  square  to  divide  a  board 
into  any  number  of  equal  parts.  For  example,  to  divide  a  board 
into  four  equal  parts,  place  the  points  of  the  blade  on  the  edges 
of  the  piece,  then  6,  12  and  18,  will  be  the  points  of  division.  If 
five  pieces  are  required,  place  the  heel  of  the  square  and  the 
figure  20  on  the  edges  of  the  piece,  then  4,  8,  12  and  16  are  the 
points  of  division.  - 
«  Figure  2. — Exhibits  the  application  of  the  square  to  find  the 
points  for  eight- squaring  timber.  Also  to  cut  a  piece  to  fit  any 
angle,  by  extending  the  line  of  the  blade  to  A  :  place  the  square 
on  the  piece,  transfer  the  distance  extended,  and  draw  the  line  A 
B,  the  angle  required. 

Figure  3. — Exhibits  the  application  of  the  square  to  find  the 
angles  of  the  octagonal  figure. 

To  find  the  cuts  in  the  mitre-box. — At  Figure  4,  place  the 
square  at  equal  distances  from  the  heel,  on  the  line  A  B.  Ta 
prove  the  truth  of  the  lines,  reverse  the  bevel.  To  find  the  per- 
pendicular and  horizontal  cuts  of  rafters  with  the  square,  take 
half  the  width  of  the  building  for  the  run,  on  the  blade,  and  the 
rise  on  the  tongue. 

Figure  5. — Exhibits  two  rules  for  finding  the  backing  of  hip- 
rafters  ;  one  with '  the  square,  as  follows  :  Place  the  square  on 
the  line  D  E,  with  the  height  H  B  on  the  tongue,  and  the  length 
A  B  on  the  blade  ;  then  the  direction  of  the  tongue  gives  the 
angle  required.  For  an  obtuse  and  acute  angled  roof  ;  for  the 
obtuse  angled  hip,  place  the  length  of  the  acute  angled  hip  rafter 
on  the  blade,  and  the  height  on  the  tongue,  then  the  tongue  gives 
the  angle  required.  The  same  operation  on*  the  obtuse  angled 
hip  rafter  gives  the  angle  to  bevel  the  acute  angled  rafter. 

The  other  rule  is  geometrical  and  applies  to  right,  obtuse,  and 
acute  angles  where  the  pitches  are  the  same,  as  follows  :  From 
the  point  D  as  centre,  describe  an  arc  from  the  line  L  K ;  tangent 
to  the  arc,  draw  the  dotted  line  parallel  to  D  A,  cutting  the  line 
A  H  at  I ;  draw  I  J  parallel  to  AB  ;  then  the  line  I.  J  gives  the 
distance  to  gauge  the  rafter  for  the  backing,  as  shown  at  section 
G. 


POSTS.  23 


POSTS. 

According  to  the  experiments  of  Rondelet,  when  the 
height  of  a  square  post  is  less  than  about  seven  or  eight 
times  the  size  of  its  base,  it  cannot  be  bent  by  any  pres- 
sure less  than  that  which  would  crush  it.  The  internal 
mechanism  of  the  resisting  forces  when  timber  yields  by 
crushing  is  not  exactly  understood.  In  timber,  the  resist^ 
ance  to  crushing  is  less  than  the  cohesive  force.  The 
resistance  of  timber  to  crushing  appears  to  increase  in  a 
higher  ratio  than  that  ol  the  area  of  its  section. 

The  load  a  piece  of  timber  will  bear,  when  pressed  in 
the  direction  of  its  length,  without  risk  of  being  crushed, 
may  be  found  by  the  following  rule: 

Multiply  the  area  of  the  piece  of  timber,  in  inches,  by 
the  weight  that  is  capable  of  crushing  a  square  inch  of 
the  same  kind  of  wood,  then  one-fourth  of  the  product 
will  give  the  load,  in  pounds,  that  the  piece  would  bear 
with  safety. 

If  the  area  that  would  support  a  given  weight  be  re- 
quired, divide  four  times  the  weight  by  the  number  of 
pounds  that  would  crush  a  square  inch,  and  the  quotient 
is  the  area  in  inches. 

The  length  should  never  exceed  ten  times  the  side  of 
the  section,  to  give  the  above  results ;  for,  when  the 
length  is  greater  than  about  ten  times  the  thickness,  the 
piece  will  bend  before  it  crushes. 


CARPENTRY. 


PLATE  10. 

To  form  an  ellipse  with  a  thread  or  string. 

At  Fig.  i,  draw  the  major  and  minor  axes,  A  B  and 
C  D.  To  find  the  points  for  the  pins,  to  describe  the  ellipse : 
from  the  point  C  as  centre,  with  E  B  as  radius,  describe 
arcs  cutting  the  major  axis  at  2  and  3,  the  points  required ; 
around  the  pins  and  the  point  C  place  a  cord  ;  with  the 
pencil  placed  at  the  point  C,  describe  the  ellipse  re- 
quired. Care  should  be  taken  to  keep  the  cord  at  an  even 
tension. 

To  draw  a  polygon  of  any  number  of  sides. 

To  form  a  polygon  of  five  sides. — From  the  point  A, 
Fig.  2,  as  centre,  with  the  given  side  A  B  as  radius,  de- 
scribe a  semi-circle,  which  divide  into  five  equal  parts ; 
through  the  points  of  division,  draw  A  2,  A  3  and  A  4,  in- 
definitely ;  parallel  to  A  3  and  A  4,  draw  B  C  and  2  D  ; 
join  C  D,  which  completes  the  polygon  required. 

To  form  the  false  ellipse. 

Figure  3.  Draw  the  major  and  minor  axes,  A  B  and 
C  D  ;  join  B  C,  and  divide  into  three  equal  parts ;  draw 
N  E  at  right  angles  to  C  B  :  from  the  point  E  as  centre,  with 
E  C  as  radius,  describe  the  arc  R  N :  from  the  point  S  as 
centre,  with  S  B  as  radius,  describe  the  arc  N  P.  The 
opposite  sides  are  found  in  the  same  manner. 

Figures  4,  5  and  6  are  simple  geometrical  operations, 
aji  inspection  of  which  is  sufficient  for  their  comprehen- 
sion. 


/ 


TABLES  25 


WEIGHT  IN  POUNDS 

OF  A  CUBIC  FOOT  OF  WOOD  OR  STONE. 


WOOD.  STONE. 


Apple-tree, 

49.6 

Flint, 

163.2 

Ash,  » 

-  52-9 

Blue  Granite, 

-    164. 1 

Birch, 

33-2 

Limestone, 

199. 

American  Cedar,  - 

-  35-i 

Grindstone, 

-  134. 

Elm, 

42. 

Slate  Stone, 

167. 

White  Pine, 

-  35-6 

Marble, 

-  170. 

"Yellow  Pine,  - 

4f.t 

Freestone, 

150. 

Mahogany, 

-  66.5 

African  Marble,  - 

-  169.2 

Maple,  - 

47- 

Egyptian  Marble, 

166.8 

Mulberry,  . 

-  561 

Italian  Marble, 

-  166.1 

Oak,  - 

58-74 

Roman  Marble, 

172.2 

Live  Oak, 

-  70- 

OTHER  SUBSTANCES. 

Cast  Iron,  - 

450-55 

Air,  - 

.07529 

Wrought  Iron,  - 

-  486.65 

Steam, 

-  .03689 

Steel,  - 

489.8 

Loose  Earth  or  Sand, 

95- 

Copper,  - 

-  555- 

Common  Soil, 

124. 

Lead,  - 

708.75 

Strong  Soil, 

127. 

Brass, 

-  537-75 

Clay,    -  - 

135. 

Tin,  - 

456- 

Clay  and  Stones, 

160. 

Salt-water,  (Sea,) 

-  64.3 

Cork, 

15. 

Fresh-water,  - 

62.5 

Brick,  - 

"5- 

Tallow,  - 

59- 

26 


CARPENTRY. 


PLATE  11. 

Shows  a  timber  foundation  for  a  frame  building,  with  two> 
side  elevations,  framed  in  the  visual  manner  for  good  houses. — 
The  object  of  this  and  the  following  Plates,  is  first  to  give 
the  inexperienced  workman  the  names  used  among  car- 
penters and  joiners,  of  the  different  pieces  of  timber  used 
in  framing,  and  where  they  are  placed  ;  also  to  show  the 
method  of  constructing  what  is  called  a  balloon  frame. 

Figure  i. — Shows  a  timber  plan  of  foundation  support- 
ed by  brick  or  stone  walls.  The  outside  timbers  are 
called  sills;  and,  if  there  are  no  openings,  all  other  timbers 
are  called  beams;  but  when  there  are  openings  for  chim- 
neys or  stair-ways,  the  workman  will  be  required  to  mor- 
tise and  tenon  the  timbers  together  as  shown  on  the  plan. 
The  first  piece  of  timber  to  prepare  will  be  the  trimmert 
shown  at  A,  which  is  tenoned  into  the  trimmer-beams \ 
shown  at  BE.  The  short  beams  tenoned  into  the  trim7ner 
are  called  tail-beams.'  Figs.  2  and  3  are  the  front  and  a 
portion  of  the  side  elevation  of  the  frame  standing  on  the 
foundation,  showing  the  posts,  beams,  enter-ties,  plates, 
rafters  and  braces  in  their  proper  places.  The  timbers 
shown  at  A  A,  Fig.  2,  are  called  frame-beams;  D  D, 
corner-posts,  and  C  C,  rafters.  At  Fig.  3,  A  shows  what 
should  be  called  an  intermediate  post;  the  pieces  of  timber 
called  enter-ties,  are  shown  at  E  E  ;  the  piece  of  timber 
supporting  the  rafters  at  C,  represents  the  plate,  and  B  B 
the  sills;  the  oblique  pieces  of  timber  shown  on  the  ele- 
vations, are  called  braces;  the  timbers  shown  on  each  side 
of  the  openings  are  called  joists,  and-  termed  door  and 
window  joist;  those  placed  between  doors  and  windows,, 
are  called  intermediate  joists,  or  furrings ;  all  joists  cut 
under  or  over  the  braces  are  called  cripples;  a  piece  of 
timber  placed  on  piers  for  the  purpose  of  supporting  other 
timbers  or  partitions,  are  called  summers;  a  piece  of  tim- 
ber placed  on  a  truss-frame,  for  the  purpose  of  supporting 
the  common  rafters,  is  called  a  purlin. 


J 


/ 


NAILS.  2? 


ADHESION  OF  NAILS, 

Every  carpenter  is  familiar  with  the  use  of  nails,  and 
possesses  a  practical  knowledge,  more  or  less  accurate  of 
the  force  of  adhesion  of  different  nails,  and  in  different 
substances,  so  as  to  deci.de,  without  difficulty,  what  num- 
ber, and  of  what  length,  may  be  sufficient  to  fasten  to- 
gether substances  of  various  shapes,  and  subject  to  various 
strains.    But  interesting  as  this  subject  unquestionably  is, 
it  has  not  been  till  very  recently  that  the  necessary  experi-  • 
ments  have  been  made  to  determine :  ist,  the  adhesive 
force  of  different  nails,  when  driven  into  wood  of  different^ 
species ;  2d,  the  actual  weight,  without  impulse,  necessary  ' 
to  force  a  nail  a  given  depth  ;  and  3d,  the  force  required 
to  extract  the  nail  when  so  driven.    The  obtaining  of  this 
useful  knowledge  was  reserved  for  Mr.  B.  Bevan,  a  gen- 
tleman well  known  in  the  mechanical  and  scientific  world: 
for  the  accuracy  with  which  his  experiments  are  con-: 
ducted. 

Mr.  Bevan  observes,  that  the  theoretical  investigation 
points  out  an  equality  of  resistance  to  the  entrance  and  ex~ 
traction  of  a  nail,,  supposing  the  thickness  to  be  invariable ; 
but  as  the  general  shape  of  nails  is  tapering  towards  the 
point,  the  resistance  of  entrance  necessarily  becomes 
greater  than  that  of  extraction ;  in  some  experiments  he 
found  the  ratio  to  be  about  6  to  5. 

The  percussive  force  required  to  drive  the  common  six- 
penny nail  to  the  depth  of  one  inch  and  a  half,  into  dry 
Christiana  deal,  with  a  cast  iron  weight  of  6.275  lt>s-  was 
four  blows,  or  strokes,  falling  freely  the  space  of  1 2  inches; 
and  the  steady  pressure  to  produce  the  same  effect  was 
400  lbs. 


{Continued  on  page  29.) 


28 


CARPENTRY. 


PLATE  12. 

Shows  the  method  of  constructing  what  is  termed  a  balloon 
frame. 

Fig-,  i  shows  the  timber  plan  ;  Figs.  2  and  3,  the  front 
and  side  elevations.  The  foundation  timbers  should  be  ot 
white  pine ;  all  other  timbers,  of  spruce  or  Eastern  pine. 
All  the  tools.the  workman  requires  to  construct  a  frame 
of  this  kind,  are  a  saw,  hammer  and  chisel.  The  side-sills 
should  be  4x4  inches  ;  front  and  rear-sills,  four  inches 
thick;  beams  2x8  or  ten  inches,  according  to  their  length 
and  the  load  they  are  required  to  carry.  Corner  post  4x4 
inches  ;  door  and  window  joists,  3x4  inches  ;  all  other  in- 
termediate joists,  2x4  inches  r  plates,  4x4  inches  ;  rafters, 
3x5  inches.  The  two  outside  beams,  in  second  story,  are 
spiked  to  the  joists  ;  those  resting  on  the  plates  are  spiked 
to  the  rafters.  The  enter-ties  require  to  be  1^x4  inches 
let  into  the  joists  to  support  second  story  beams.  Each 
tier  of  beams  should  have  one  or  two  courses  of  bridging. 
When  the  frame  is  completed  and  sheathed  with  one  inch 
worked  boards,  placed  diagonally  and  securely  nailed  to 
-every  joist,  it  will  be  quite  as  substantial  and  safe  as  a 
frame  made  in  the  usual  manner. 


NAILS.  28 


ADHESION  OF  NAILS. 

A  sixpenny  nail  driven  into  dry  elm,  to  the  depth  of  one 
inch,  across  the  grain,  required  a  pressure  of  327  pounds 
to  extract  it;  and  the  same  nail,  driven  endways,  or  longi- 
tudinally, into  the  same  wood,  was  extracted  by  a  force 
of  257  pounds. 

The  same  nail  driven  two  inches,  endways,  into  dry 
Christiana  deal,  was  drawn  by  a  force  of  257  pounds  ;  and 
to  draw  out  one  inch,  under  like  circumstances,  took  87 
pounds  only.  The  relative  adhesion,  therefore,  in  the  same 
wood,  when  driven  transversely  and  longitudinally,  is  100 
to  78,  or  about  4  to  3,  in  dry  elm  ;  and  100  to  46,  or  about 
2  to  1,  in  deal;  and,  in  like  circumstances,  the  relative  ad- 
hesion to  elm  and  deal  is  as  2  or  3  to  1. 

The  progressive  depths  of  a  sixpenny  nail  into  dry 
Christiana  deal  by  simple  pressure  were  as  follows  : — 

One-quarter  of  an  inch,  a  pressure  of  24  lbs. 


Half  an  inch,       -       -       -       -       76  ' 4 

One  inch,         -----  235  " 

One  inch  and  a  half,     -                    400  " 

Two  inches,      -                                610  " 


In  the  above  experiments,  great  care  was  taken  by  Mr* 
Bevan  to  apply  the  weight  steadily  ;  and  towards  the 
conclusion  of  each  experiment,  the  additions  did  not  ex- 
ceed 10  pounds  at  one  time ;  with  a  moderative  interval 
between,  generally  about  one  minute,  sometimes  10  or  20 
minutes.  In  other  species  of  wood,  the  requsite  force  to 
extract  the  nail  was  different.  Thus,  to  extract  a  com- 
mon sixpenny  nail  from  a  depth  of  one  inch  out  of 

Dry  Oak,  required     -       -       -       507  lbs. 
Dry  Beech,    -  667  " 

Green  Sycamore,       -  313  " 

From  these  experiments,  we  may  infer  that  a  common 
sixpenny  nail,  driven  two  inches  into  oak,  would  require 
a  force  of  more  than  one-half  a  ton  to  extract  it  by  a 
steady  force. 


80 


CARPENTRY. 


PLATE  13. 

Carpentry  is  the  art  of '  cutting  and jointing  timbers  ZTi, 
the  construction  of  buildings.  ' 

To  cut  timbers  and  adapt  them  to  their  various  situa- 
tions, so  that  one  of  the  sides  of  every  piece  shall  be  ar- 
ranged according  to  a  given  plane  or  surface  shown  in  the 
designs  of  the  architect,  is  a  department  of  carpentry  which 
requires  a  thorough  knowledge  of  the  finding  of  sections 
of  solids,  their  coverings,  and  the  various  methods  ot 
connecting  timbers,  etc. 

The  art  of  combining  pieces  of  timber  to  increase  their 
strength  and  firmness,  is  called  framing. 

The  form  of  a  frame  should  be  adapted  to  the  nature  cf 
the  load  which  it  is  designed  to  carry. 

In  carpentry,  the  load  is  usually  distributed  over  the 
whole  length  of  the  framing,  but  it  is  generally  supported 
from  point  to  point,  by  short  beams  or  joists. 

First,  let  us  consider  a  case  where  the  load  is  collected 
at  one  point  of  the  frame  ;  and,  in  order  that  the  advantage 
of  framing  may  be  more  obvious,  let  us  suppose  all  the 
parts  of  a  certain  piece  of  frame-work  to  be  cut  out  of  a 
single  beam,  which,  in  a  solid  mass,  would  be  too  weak 
for  the  purpose. 

Let  Fig.  i  be  a  piece  of  timber,  cut  in  the  various  direc- 
tions indicated  by  the  lines  passing  through  it,  and  let  the 
triangular  piece  shown  at  Eand  F  be  removed  ;  then  raise 
the  pieces  A  E  and  A  F  till  they  make  close  joints  at  E  and 
F,  and  increase  their  lengths  till  they  form  a  frame,  or 
truss,  as  represented  at  Fig.  2.  A  small  rod  of  iron  with 
suitable  nuts,  will  be  required  to  support  the  centre  of  the 
tie,  as  seen  in  the  drawing.  If  the  depth  of  the  frame  at 
the  middle  be  double  the  depth  of  the  beam,  the  strength 
of  the  frame  will  be  a  little  more  than  eight  times  as  great 
as  that  of  the  beam.  If  the  depth  of  the  frame  be  three 
times  the  depth  of  the  beam,  as  represented  at  Fig.  2,  it 
will  be  about  six  times  as  strong  as  the  beam,  and  about 
eighteen  times  as  firm  ;  that  is,  it  will  bend  only  an  eight- 
eenth part  of  the  distance  which  the  beam  would  bend, 
under  the  same  weight. 

To  render  the  strength  more  equal,  and  to  obtain  two 
points  of  support,  there  may  be  a  level  piece  of  timber 
placed  between  the  inclining  ones,  as  shown  at  Fig.  3  ;  but 
if  a  greater  weight  be  placed  at  G  than  at  H,  there  will 
be  a  tendency  to  spring  upwards  at  H,  and  inwards  at  A, 
which  may  be  effectually  prevented  by  the  suspension  rod 
Ji  A,  as  shcvn  in  the  same  figure* 


Tig.6. 


FRAMING.  31 


It  now  remains  to  show  why  the  strength  of  a  piece  of 
timber  is  increased  by  forming  it  into  a  truss;  and  to  have 
a  clear  conception  of  this  subject  is  of  the  utmost  impor- 
tance in  the  science  of  carpentry. 

Let  ABC,  Fig.  4,  be  a  truss  to  support  a  weight  applied 
at  A.  It  is  evident  that  the  force  of  the  weight  will  tend 
to  spread  the  abutments,  B  and  C,  and  the  nearer  we 
reduce  the  angle  A  B  C  to  a  straight  line,  the  greater  will 
be  the  pressure,  or  tendency  to  spread  or  increase  at  A. 
On  the  contrary,  if  the  height  be  increased,  as  at  Fig.  5, 
the  tendency  to  spread  the  abutment  will  be  less. 

The  advantage  of  framing  timbers  together  for  the 
purpose  of  giving  strength  and  firmness  having  been 
shown,  let  us  proceed  to  explain  how  the  strain  on  any 
part  may  be  measured. 

To  find  the  pressure  on  oblique  supports  or  parts  of 
trusses,  frames,  etc.  Let  A  C,  Fig.  6,  be  a  heavy  beam 
supported  by  two  posts,  A  C  and  B  D,  placed  at  equal 
distances  from  E,  the  centre  of  the  beam.  The  pressure  on 
each  post  will  obviously  be  equal  to  half  the  weight  of  the 
beam.  But  if  the  posts  be  placed  obliquely,  as  in  Fig.  7, 
the  pressure  on  each  post  will  be  increased  in  the  same 
proportion  as  its  length  is  increased,  the  height  A  C  being 
the  same  as  before;  that  is,  when  A  F  is  double  AC,  the 
pressure  on  the  post  in  the  direction  of  its  length  is  double 
half  the  weight  of  the  beam.  Hence  it  is  very  easy  to  find 
the  pressure  in  the  direction  of  an  inclined  strut,  for  it  is  as 
many  times  half  the  weight  supported  as  A  C  is  contained 
in  A  F.  Therefore,  if  the  depth  A  C  of  a  truss  to  support 
a  weight  of  two  tons  be  only  one  foot,  and  A  F  be  ten 
feet,  the  pressure  in  the  direction  of  A  F  will  be  ten  tons. 

It  will  be  observed  that  when  the  beam  is  supported 
by  oblique  posts,  as  in  Fig.  7,  these  posts  will  slide  out  at 
the  bottom,  and  together  at  the  top,  if  not  prevented  by 
proper  abutments.  The  force  with  which  the  foot  F 
tends  to  slide  out  is  to  half  the  weight  of  the  beam  A  B, 
as  F  C  is  to  A  C.  Therefore,  when  F  C  is  equal  to  A  C, 
the  tendency  to  slide  out  is  equal  to  half  the  weight  sup- 
ported ;  and  if  F  C  be  ten  times  A  C,  the  tendency  to 
spread  out  would  be  ten  times  the  weight  supported. 
Hence  it  is  evident  that  a  flat  truss  requires  a  tie  of  im- 
mense strength  to  prevent  it  from  spreading.  If  a  flat 
truss  produces  any  degree  of  stretching  in  the  tie,  the 
truss  must  obviously  settle,  and  by  settling  it  becomes 
flat,  and  consequently  exerts  a  greater  strain.  In  a  flat 
truss,  therefore,  too  much  caution  cannot  be  used  in  fit- 
ting the  joints  and  choosing  good  materials. 


82  CARPENTRY. 


PLATE  14. 

In  framing,  all  pieces  placed  at  right  angles  to  each 
other  are  cut  square  or  beveled ;  but  when  placed  diag- 
onally and  oblique  to  the  base,  require  a  geometrical 
operation  to  find  a  section  of  the  piece  whose  sides 
shall  be  in  the  plane  of  those  it  is  connected  with.  It 
is  intended,  therefore,  to  present,  at  this  time,  a  new 
and  complete  system  of  lines  for  finding  sections"  and 
cuts  of  pieces  placed  in  any  position,  from  the  horizontal 
to  the  perpendicular,  by  means  of  tangents  and  circles. 

Let  A  B  C  D,  Fig.  i,  represent  the  plan  of  a  right- 
angled  hip-roof,  and  B  F  C  the  elevation.  To  find  a  sec- 
tion of  the  hip-rafters,  draw  G  H  at  right  angles  to  B  E; 
from  the  point  H  as  centre,  with  H  J  as  radius,  describe 
an  arc ;  from  the  point  G,  draw  the  tangent,  cutting  the 
line  B  E  at  R ;  join  H  R,  which  forms  the  angle  for  the 
section  required. 

To  find  the  lengths  of  the  hip  and  jack-rafters.  Draw 
D  L,  Fig.  i,  equal  to  the  common  rafter  C  F,  Fig.  2 ;  join 
CL  for  the  length  of  the  hip-rafters.  To  find  the  lengths 
of  the  jack-rafters,  divide  the  common  rafter  D  L  into 
as  many  parts  as  there  are  jack-rafters  required. 

To  find  the  bevels  for  the  hip  and  jack-rafters.  Draw 
C  N,  Fig.  1,  equal  to  C  E,  and  LN  equal  to  P  F,  Fig.  2; 
then  in  the  angle  at  L  is  the  down  bevel,  and  at  C  the  face 
bevel,  for  the  hip-rafters.  The  face  and  down  bevels  for 
the  jack  rafters  are  shown  at  E  and  F. 

Figure  3  exhibits  the  application  of  the  foregoing 
system  to  an  obtuse  and  acute-angled  plan ;  the  operation 
is  precisely  the  same,  and  consequently  needs  no  further 
explanation. 


SCREWS.  33 


ADHESION  OF  SCREWS. 

A  common  screw,  of  one-fifth  of  an  inch,  was  found  to 
have  an  adhesive  force  of  about  three  times  that  of  a  six- 
penny nail. 


ADHESION  OF  IRON  PINS. 

The  force  necessary  to  break  or  tear  out  a  half-inch 
iron  pin,  applied  in  the  manner  of  a  pin  to  a  tenon  in  the 
mortise,  has  likewise  obtained  the  attention  of  the  same 
celebrated  experimentalist.  The  thickness  of  the  board 
was  0.87  inch,  and  the  distance  of  the  center  of  the  hole 
from  the  end  of  the  board,  1.05  inch.  The  force  required 
was  916  lbs. 

As  the  strength  of  a  tenon  from  the  pin-hole  may  be 
considered  in  proportion  to  the  distance  from  the  end, 
and  also  as  the  thickness,  we  may,  for  this  species  of 
wood,  obtain  the  breaking  force  in  pounds,  nearly,  by 
multiplying  together  one  thousand  times  the  distance  of 
the  hole  from  the  end,  by  the  thickness  of  the  tenon,  in 
inches. 


LENGTH  OF  IRON  NAILS. 

AND   NUMBER  TO  A  POUND. 


SIZE. 

LENGTH. 

NO. 

SIZE. 

LENGTH. 

NO. 

3d 

1 J  in. 

420 

iod 

3  in- 

65 

4d 

\\  in. 

270 

12d 

34  in. 

5* 

5<l 

if  in. 

220 

2Qd 

3i  in. 

28 

6d 

2  in. 

175 

3o< 

4  in. 

24 

8d 

2-£  in. 

IOO 

4od 

4i  in. 

20 

34 


CARPENTRY. 


PLATE  15. 

FIGURE  I. — Exhibits  rules  for  finding  the  backing  of  the 
hip-rafters,  the  lengths  and  cuts  of  jack-rafters,  where  the 
pitches  are  not  at  the  same  angle  of  elevation. 

Let  ABC  and  D  be  the  plan  of  the  roof,  A  E  B  the 
plan  of  the  hips,  F  G  and  J  H  the  height  of  the  rafters ; 
join  A  G  and  A  H  ;  then  A  G  will  be  the  pitch  of  the  roof 
over  the  line  E  J,  and  A  H  the  pitch  over  the  line  E  F, 
and  E  A  the  line  of  intersection.  The  down  and  face 
bevels  for  the  jack-rafters  and  hips  are  all  shown  ;  the 
principle  and  method  of  finding  the  section  of  the  hip  are 
the  same  as  shown  on  Plate  6. 

Figure  2. — Exhibits  the  method  of  finding  the  distance  to 
kerf  the  back  string  for  a  circular  stairs  so  that  when  secured 
in  its  place  the  saw -kerfs  shall  be  closed. 

To  find  the  distance  the  saw-kerfs  shall  be  from  each 
other,  make  C  D  equal  the  radius  of  the  required  circle 
shown  at  A  B,  then  take  a  piece  the  thickness  of  the  string- 
piece,  any  width  ;  make  a  saw-kerf  in  the  centre  as  shown 
at  C  ;  secure  the  piece  at  C  and  F  ;  move  the  piece  from 
D  until  the  saw-kerf  is  closed  at  C,  which  will  give  the 
points  for  the  saw-kerfs  required,  as  shown  on  the  curve 
line  at  E  and  D. 

FIGURE  3. — Exhibits  a  very  cheap  and  expeditious  plan 
for  framing  a  roof  to  span  from  forty  to  seventy  feet. — It 
requires  no  explanation,  further  than  to  say  that  the  tie 
need  not  be  more  than  5x8  inches  ;  the  rafters  and  braces 
5x5  inches  ;  the  battens,  of  one  inch  boards  spiked  to  the 
timbers  with  large  nails.  It  is  believed  to  be  the  best  roof 
that  can  be  constructed,  as  it  has  all  the  advantages  of  a 
solid  mass,  without  the  great  weight  and  the  disadvantages 
of  the  shrinkage  of  material,  which  is  almost  entirely 
obviated  by  the  crossing  of  the  fibres  of  the  wood. 


GLUE.  36 


ADHESION  OF  GLUE. 

Mr.  Bevan  glued  together,  by  the  ends,  two  cylinders 
of  dry  ash  wood,  one-fifth  of  an  inch  diameter  and  about 
eight  inches  long ;  after  they  had  been  glued  together  24 
hours,  they  required  a  force  of  1,260  pounds  to  separate 
them  ;  and,  as  the  area  of  the  circular  ends  of  the  cylin- 
ders was  1.76  inches,  it  follows  that  the  force  of  71 5  pounds 
would  be  required  to  separate  one  square  inch. 

It  is  right  to  observe,  that  the  glue  used  in  this  experi- 
ment was  newly  made,  and  the  season  very  dry.  For  in 
some  former  experiments  on  this  substance,  made  in  the 
winter  season,  and  upon  some  glue  which  had  been  fre- 
quently made  by  occasional  additions  of  glue  and  water, 
he  obtained  a  result  of  350  to  560  pounds  to  the  square 
inch. 

The  present  experiment,  however,  was  conducted  upon 
a  larger  scale,  and  with  greater  care  in  the  direction  of 
the  resultant  force,  so  that  it  might  be,  as  near  as  practi- 
cable, in  a  line  passing  at  right  angles  through  the  centres 
of  the  surfaces  in  contact.  The  pressure  was  applied 
gradually,  and  was  sustained  two  or  three  minutes  before 
it  separated. 

Upon  examining  the  separated  surfaces,  the  glue  ap- 
peared to  be  very  thin,  and  did  not  entirely  cover  the 
wood,  so  that  the  actual  adhesion  of  glue  must  be  some- 
thing greater  than  715  pounds  to  the  square  inch. 

Mr.  Bevan  also  tried  the  lateral  cohesion  of  fir-wood, 
from  a  Scotch  fir  of  his  own  planting,  cut  down  in  the 
autumn,  sawn  into  boards,  and,  at  the  time  of  experiment, 
quite  dry  and  seasoned.  The  force  required  to  separate 
the  wood,  was  562  pounds  to  the  square  inch  ;  conse- 
quently, if  two  pieces  of  this  wood  had  been  well  glued 
together,  the  wood  would  have  yielded  in  its  substance 
before  the  glue. 

In  a  subsequent  experiment,  made  on  solid  glue,  the 
cohesive  force  was  found  to  be  4,000  pounds  per  square 

{Continued  on  page  37.) 


30 


CARPENTRY. 


PLATE  16. 

Exhibits  the  plan  of  a  roof  with  internal  angles  formed 
by  a  transept  and  gable  placed  opposite  each  other. 

Let  A  B  and  C  D  represent  the  plan  of  the  valley-rafters  ; 
Fig.  i  and  Fig.  2,  the  elevations  of  the  roofs.  To  find  a 
section  of  the  valley-rafters,  draw  the  dotted  line  S  L,  at 
right  angles  to  C  D  :  from  the  points  S  and  L  as  centres, 
describe  arcs  touching  the  lines  C  J  and  C  P;  tangent  to 
the  arcs,  draw  lines  from  L  and  S,  intersecting  on  the 
line  C  D,  forming  the  internal  angle  required  for  the 
valley-rafters.  The  face-bevels  for  the  hips  and  jack- 
rafters  are  shown  at  3  and  4.  The  down-bevel  for  the  hip- 
rafters  is  shown  at  2.  The  down-bevels  for  the  common 
and  jack-rafters  are  shown  at  J  and  P.  At  A  is  shown  a 
section  of  the  valley-rafters  for  the  gable  AD. 

Figure  3. — Exhibits  the  plan  and  elevation  of  a  grain- 
mill  hopper  ;  giving  the  exact  form  of  the  sides,  also  the 
angle  to  mitre,  or  butt  the  joints,  with  the  angle-piece  ta 
secure  the  same. 


/ 


GLUE.  37 


inch  ;  from  which  it  may  be  inferred  that  the  application 
of  this  substance  as  a  cement  is  susceptible  of  improve- 
ment. 

Glues  are  found  to  differ  very  much  from  each  other, 
in  their  consistence,  color,  taste,  smell,  and  solubility. 
Some  will  dissolve  in  cold  water,  by  agitation;  while 
others  are  soluble  only  at  the  point  of  ebullition.  The 
best  glue  is  generally  admitted  to  be  transparent,  and  of 
a  brown  yellow  color,  without  either  taste  or  smell.  It  is 
perfectly  soluble  in  water,  forming  a  viscous  fluid,  which, 
when  dry,  preserves  its  tenacity  and  transparency  in 
every  part,  and  has  solidity,  color,  and  viscidity,  in  pro- 
portion to  the  age  and  strength  of  the  animal  from  which 
it  is  produced.  To  distinguish  good  glue  from  bad,  it  is 
necessary  to  hold  it  between  the  eye  and  light  ;  and  if  it 
appears  of  a  strong  dark  brown  color,  and  free  from 
cloudy  or  black  spots,  it  may  be  pronounced  to  be  good. 
The  best  glue  may  likewise  be  known  by  immersing  it  in 
cold  water  for  three  or  four  days,  and  if  it  swells  consid- 
erably without  melting,  and  afterwards  regains  its  former 
dimensions  and  properties  by  being  dried,  the  article  is  of 
the  best  quality. 

In  preparing  glue  for  use,  it  should  be  softened  and 
-swelled  by  steeping  it  in  cold  water  for  a  number  of 
hours.  It  should  then  be  dissolved,  by  gently  boiling  it 
till  it  is  of  a  proper  consistence  to  be  easily  brushed  over 
any  surface.  A  portion  of  water  is  added  to  glue,  to 
make  it  of  a  proper  consistency,  which  portion  may  be 
taken  at  about  a  quart  of  water  to  half  a  pound  of  glue. 
In  order  to  hinder  the  glue  from  being  burned  during  the 
process  of  boiling,  the  vessel  containing  the  glue  is  gen- 
erally suspended  in  another  vessel,  which  is  made  of  cop- 
per, and  resembles  in  form  a  tea-kettle  without  a  spout 
This  latter  vessel  contains  only  water,  and  alone  receives 
the  direct  influence  of  the  fire. 

A  little  attention  to  the  following  circumstances  will 
tend  in  no  small  degree,  to  give  glue  its  full  effect  in 
uniting  perfectly  two  pieces  of  wood  :  first,  that  the  glue 
(Continued  on  page  39.) 


CARPENTRY. 


PLATE  17. 

Exhibits  the  plan  and  elevation  of  an  obtuse  and  acute- 
angled  building. —  The  projections  of  rafters  are  supported  by 
braces. 

At  Figure  i,  A  represents  the  plan  of  the  post;  B  the 
rafter;  and  C,  the  elevation  of  the  post.  At  Fig.  4,  D 
represents  the  plate,  and  the  elevation  of  the  rafter.  To 
find  the  bevel  for  the  lower  edge  of  the  brace,  draw  F  G 
parallel  to  the  edge  of  the  post;  draw  the  under  side  of 
the  brace  at  H  equal  in  width  to  B,  Fig.  1.  Then,  from 
the  point  G  as  centre,  describe  an  arc  ;  from  the  tangent 
F  G,  tangent  to  the  arc,  draw  a  line  at  right  angles  to 
the  brace ;  join  the  points  of  intersection  for  the  angle 
required.  The  bevel  for  the  edge  of  the  rafter,  when  in 
the  plane  of  the  roof,  is  given  at  E  ;  the  bevel  for  the 
butt  joint  at  the  apex,  or  peak  of  the  roof,  is  given  at  F,. 
Fig.  4. 

FIGURE  5. —  To  draw  a  line  forming  equal  angles  with  two 
converging  lines.  Draw  the  converging  lines  A  D  and 
B  C,  indefinitely.  At  any  point  H,  draw  H  I  parallel  to 
A  D,  and  H  G  parallel  to  B  C  :  from  the  points  I  and  G 
as  centres,  describe  arcs;  through  the  points  of  intersec* 
tion,  draw  E  F,  the  line  required. 


GLUE. 


39 


be  thoroughly  melted,  and  used  while  boiling  hot ;  sec- 
ondly, that  the  wood  be  perfectly  dry  and  warm ;  and 
lastly,  that  the  surfaces  to  be  united  should  be  covered 
only  with  a  thin  coat  of  glue,  and  after  having  been 
strongly  pressed  together,  left  in  a  moderately  warm  sit- 
uation, till  the  glue  is  completely  dry.  When  it  so  hap- 
pens that  the  face  of  surfaces  to  be  glued  cannot  be  con- 
veniently compressed  together  in  any  great  degree,  they 
should,  as  soon  as  besmeared  with  the  glue,  be  rubbed 
lengthwise,  one  on  the  other,  several  times,  in  order 
thereby  to  settle  them  close.  When  all  the  above  cir- 
cumstances cannot  be  combined  in  the  same  operation, 
the  hotness  of  the  glue  and  dryness  of  the  wood  should, 
at  all  events,  be  attended  to. 

The  qualities  of  glue  are  often  impaired  by  frequent 
meltings.  This  may  be  known  to  be  the  case  when  it 
becomes  of  a  dark  and  almost  black  color  ;  its  proper 
color  being  a  light  ruddy  brown  ;  yet,  even  then,  it  may 
be  restored  by  boiling  it  over  again,  refining  it,  and 
adding  a  sufficient  quantity  of  fresh  ;  but  the  fresh  is 
seldom  put  into  the  kettle  till  what  is  in  it  has  been 
purged  by  a  second  boiling. 

If  common  glue  be  melted  with  the  smallest  possible 
quantity  of  water,  and  well  mixed,  by  degrees,  with  lin- 
seed oil,  rendered  dry  by  boiling  it  with  litharge,  a  glue 
may  be  obtained  that  will  not  dissolve  in  water.  By  boil- 
ing common  glue  in  skimmed  milk  the  same  effect  may 
be  produced. 

A  small  portion  of  finely  levigated  chalk  is  sometimes 
added  to  the  common  solution  of  glue  in  water,  to 
strengthen  it  and  fit  it  for  standing  the  weather. 

A  glue  that  will  resist  both  fire  and  water  may  be  pre- 
pared by  mixing  a  handful  of  quick-lime  with  four  ounces 
of  linseed  oil,  thoroughly  levigated,  and  then  boiled  to  a 
good  thickness  and  kept  in  the  shade,  on  tin  plates,  to 
dry.  It  may  be  rendered  fit  for  use  by  boiling  it  over  a 
fire  like  common  glue. 


40 


CARPENTRY. 


PLATE  18. 

Exhibits  rules  for  finding  the  lines  to  cut  a  mitre-box  for 
sprung  mouldings  ;  also  the  plans  and  elevations  for  octagonal 
and  hexagonal  roofs,  to  find  the  lengths  and  cuts  of  the  angle 
and  jack-rafters. 

Let  A,  Fig",  i,  represent  the  elevation  of  the  sprung 
moulding,  C  D  the  mitre  joint,  and  N  the  angle.  To  find 
the  bevels  (or  the  top  and  side  of  the  box :  from  the  point 
E  as  centre,  with  E  G  as  radius,  describe  the  semi-circle 
F  H  :  draw  E  1  at  right  angles  to  E  G  ;  from  the  points 
F  G  1  and  H.  draw  lines  at  right  angles  to  F  H,  indefin- 
itely ;  draw  C  K  and  D  J  parallel  to  F  H ;  join  L  K  and 
L  J.  The  bevel  lor  the  top  of  the  box  is  shown  at  M  ;  for 
the  side  of  the  box,  at  N. 

Figure  2.— Represents  the  plan  and  elevation  of  an 
octagonal  roof.  To  find  the  backing  of  the  angle-rafters  : 
from  the  point  II  as  centre,  describe  an  arc  touching  the 
line  E  G,  tangent  to  the  arc  ;  draw  B  I;  join  II  J,  the 
angle  required.  — To  find  the  length  of  the  angle  and  jack- 
rafters,  draw  K  L  equal  to  F  G;  then  L  D  equals  the 
length  of  the  angle-rafters  :  the  length  of  the  jack-rafters 
depends  on  the  distance  they  are  placed  from  each  other. 
The  face-bevel  for  the  angle  and  jack-rafters  is  shown  at 
N  :  the  down-bevel  for  the  angle-rafter  is  shown  at  O  ;  for 
the  jack-rafters,  at  G. 

Figure  3. — Represents  the  plan  and  elevation  of  a  hex- 
agonal roof.  The  rules  for  finding  the  angles  and  cuts  of 
the  rafters  are  the  same  as  shown  in  the  preceding  figure ; 
therefore,  a  bare  inspection  is  sufficient  for  its  compre- 
hension. 


METRIC  SYSTEM. 


ft 


METRIC  SYSTEM  OF  WEIGHTS  AND  MEASURES. 

Act  of  Congress  authorizing  the  decimal  system  of  our  weights  and  measures  : 

1.  It  shall  be  lawful,  throughout  the  United  States  of  America,  to  employ  the 
-weights  and  measures  of  the  Metric  System  ;  and  no  contract  or  dealing,  or 
pleading  in  any  court,  shall  be  deemed  invalid  or  liable  to  objection,  because  the 
weights  or  measures  expressed  or  referred  to  therein,  are  weights  or  measures 
of  the  Metric  System. 

2.  The  tables  in  the  schedules  hereto  annexed,  shall  be  recognized  in  the 
construction  of  contracts,  and  in  all  legal  proceedings,  as  establishing,  in  terms 
of  the  weights  and  measures  now  in  use  in  the  United  S  ates,  the  equivalents  of 
the  weights  and  measures  expressed  therein  in  terms  of  the  Metric  System  ;  and 
said  tables  may  be  lawfully  used  for  computing,  determining  and  expressing, 
in  customary  weights  and  measures,  the  weights  and  measures  of  the  Metric 
System. 


WEIGHTS. 


METRIC  NAME.         FRENCH  VALUE- 

Grams. 

Millier  (or  Tonneau).  .  .  .1,000,000. 

Quintal   100,000. 

Myriagram   10,000. 

Kilogram  (or  Kilo)    1,000. 

Hectogram.  ,   100. 

Dekagram   io. 

■Gram  (French  Gramme).  1 . 

Decigram  i-ioth. .  .  . 

Centigram  i-iooth 

Milligram  i-ioooth.  .  .  . 


-METRICAL.  AMERICAN  EQUIVALENT 

Measure  of  water  at  max.  density.  Avoir. 
1  cubic  meter.  .  .  .2204.6  pounds. 

1  hectoliter   220  46  " 

10  liters   22.046  " 

1  liter   2.2046  " 

1  deciliter   3.5274  ounces. 

10  cubic  centimeters.   0.3527  " 
1  cubic  centimeter.   15.432  grains. 
10th     "  "  1.5432 

10  cubic  millimeters.   0.1543  " 
1      "  "  0.0154 


LONG 

METRIC  NAME  AND  VALUE. 


MEASURE. 

AMERICAN  EQUIVALENT. 


Myriameter   10,000 

Kilometer   1,000 

Hectometer   100 

Dekameter   10 

Meter   1 

Decime.er   i-ioth 

Centimeter   i-iooth 

Millimeter  i-ioooth 


meters   6.2137  miles. 

"   0.62137  " 

"   228  feet  1  inch. 

 393-7  inches. 

"   -   39-37 

**    3-937  " 

"    0-3937  " 

  0.0394  " 


SQUARE  OR  SURFACE  MEASURE. 


METRIC  NAME  AND  VALUE. 


AMERICAN  EQUIVALENT. 


Hectare  10,000  square  meters   2.471  acres. 

^■RE   100     "         "    119  6     square  yards. 

Centiare   I     •«         "   I55Q        square  inches 


42 


CARPENTRY. 


PLATE  19. 

Exhibits  plans  and  elevations  of  octagonal  and  square  spires 
for  churches  or  bell  towers. 

To  find  the  lengths  of  the  angle  posts  at  Fig.  i.  Draw 
B  A  equal  to  C  D  ;  join  E  A  and  F  A,  the  length  required. 
The  bevel  for  the  intersection  of  the  angle  posts  is  shown 
at  A.  The  bevel  for  the  face  of  the  inter-ties  is  shown  at 
G.  The  bevel  for  the  external  angle  of  the  posts  and  the 
sides  of  the  inter-ties  is  shown  at  H. 

Figure  2  represents  the  plan  and  elevation  of  a  square 
spire,  or  tower.  The  operation  of  finding  the  lines  is  the 
same  as  in  Fig.  1. 

To  find  the  centre  of  a  circle  when  lost.  From  the 
points  A,  B,  C,  Fig.  3,  as  centres,  describe  arcs  intersect- 
ing each  other  at  G  D  and  E  F  ;  through  the  points  of 
intersection,  draw  lines  to  intersect  each  other  at  the  point 
required. 

To  erect  a  perpendicular  to  a  given  line,  from  a  given 
point.  From  the  point  C,  Fig.  4,  set  off,  each  way,  equal 
distances :  from  the  points  describe  arcs  cutting  each  other 
at  D  ;  join  C  D,  the  perpendicular  required. 


/ 


METRIC  SYSTEM.  4S 


CUBIC  MEASURE  OR  CAPACITY. 

METRIC  NAME  AND  VALUE.  AMERICAN  EQUIVALENT. 

Cubic  Measure.  Dry  Measure.  Liquid  or  Wine  Measure. 

Liters. 

Kiloliter.  . .1,000.      =  I.  cubic  meter,     1.308  cu.  yds.  . .  . 264. 17  gallons, 
(or  Stere.) 

Hectoliter..    100.     =    .1   "      "  2  bu.   3.35  pks...  26.41 

D.cal.ter..      10.      =10.  cu.  decimeters,  9.08  quarts   2.6417  " 

Liter   I.     =  1.    "        "        0.908    "    1.0567  quarts. 

Deciliter...         .1    =    .1  "         "        6.1022  cu.  in   0.845  gills. 

Centiliter..  .01  =10.  cu.  centimeters,  0.6102  "  "  ....  0.338  fl.ounces. 
Milliliter...        .001=  r.  "         "         o.o6r    "     "   0.27    fl.  drams. 

Facts  Worth  Remembering. — One  thousand  shingles,  laid  four  inches  to 
the  weather,  will  cover  one  hundred  square  feet  of  surface  ;  and  five  pounds  of 
shingle  nails  will  fasten  them  on. 

One-fifth  more  siding  and  flooring  is  needed  than  the  number  of  square  feet 
of  surface  to  be  covered,  because  of  the  lap  in  the  siding  and  matching  of  the 
floor. 

One  thousand  laths  will  cover  seventy  yards  of  surface,  and  eleven  pounds 
of  lath  nails  will  nail  them  on. 

Eight  bushels  of  good  lime,  sixteen  bushels  of  sand,  and  one  bushel  of  hair, 
will  make  enough  good  mortar  to  plaster  one  hundred  square  yards. 

A  cord  of  stone,  three  bushels  of  lime,  and  a  cubic  yard  of  sand,  will  lay  one 
hundred  cubic  feet  of  wall. 

Five  courses  of  brick  will  lay  one  foot  in  height  on  a  chimney  ;  six  bricks  in 
a  course  will  make  a  flue  four  inches  wide  and  twelve  inches  long  :  and  eight 
bricks  in  a  course  will  make  a  flue  eight  inches  wide  and  sixteen  inches  long. 

PROTECTION  AGAINST  RUST. 

For  farm  implements  of  all  kinds,  having  metal  surfaces  exposed,  for  knives 
and  forks,  and  other  household  apparatus — indeed,  for  all  metals  likely  to  be 
injured  by  oxidation,  or  "  rusting,"  the  application  furnished  to  the  American 
Agriculturist  by  the  late  Professor  Olmstead,  author  of  "Olmstead's  Natural 
Philosophy,"  etc.,  is  most  highly  rec  >mmended.  He  used  it  on  air-pumps 
telescopes,  and  various  other  apparatus  : — Take  any  quantity  of  good  lard,  and, 
to  every  pound  or  so,  add  of  common  resin  ("rosin")  an  amount  about  equal 
to  half  the  size  of  an  egg,  or  less — a  little  more  or  less  is  of  no  consequence. 
Melt  them  slowly  together,  stirring  as  they  cool.  Apply  this  with  a  cloth,  or 
otherwise,  just  enough  to  give  a  thin  coating  to  the  metal  surface  to  be  pro- 
tected. It  can  be  wiped  off  nearly  clean  from  surfaces  where  it  will  be  un- 
desirable, as  in  the  case  of  knives  and  forks,  etc.  The  resin  prevents  rancidity, 
and  the  mixture  obviates  the  ready  access  of  air  and  mo'sture.  A  fresh  appli- 
cation may  be  needed  when  the  coat  ng  is  washed  off  by  the  friction  of  beating 
storms,  or  otherw  se.  There  was  talk  of  patenting  this  recipe,  at  one  time, 
but  Prof.  Olmstead  dec  ded  to  publ  sh  it  for  the  general  good. 


44 


CARPENTRY 


PLATE  20. 

Exhibits  the  operation  of  finding  the  curve  of  what  are 
termed,  among  carpenters,  sprung  mouldings  for  circular 
cornices. 

The  stuff  from  which  they  are  obtained  is  thinner  than 
if  the  angular  piece  were  worked  on  the  moulding.  These 
mouldings  require  brackets,  as  at  Fig.  i,  placed  at  proper 
distances,  either  in  a  straight  or  curved  line.  If  they  are 
curved,  the  moulding  will  require  to  be  bent  as  in  cover- 
ing the  frustrum  of  a  cone. 

Figure  2. — Represents  the  plan  and  elevation  of  a  cir- 
cular moulding.  To  find  the  radius  to  describe  the  curve, 
produce  B  D  to  C:  from  the  point  C  as  centre,  describe 
the  curves  required.  The  curve  of  the  moulding,  when  in 
position,  is  shown  at  D  H,  and  will  require  to  be  kerfed  at 
proper  distances,  a  rule  for  which  is  given  in  plate  7, 
Fig.  2. 

Figure  3. — Exhibits  the  elevation  of  an  Ogee  cornice. 
The  centres  from  which  the  curves  are  described  are 
found  in  the  same  manner  as  in  the  preceding  figure. 

A  tangent  to  a  circle  being  given,  to  find  the  point  of  contact. 

From  the  centre  A,  Fig.  4,  describe  the  circle :  draw 
the  tangent  B  D,  indefinitely  ;  bisect  A  B  ;  from  the  point 
C,  describe  the  arc  A  B  cutting  the  circle  at  D,  the  point 
required. 


WOODS.  45 


VARIOUS  WOODS. 

The  following  are  interest'ng  items  concerning  the  commercial  value  and 
properties  of  the  better  known  woods,  as  laid  down  by  the  American  Builder. 

Elasticity  :  Ash,  hickory,  hazel,  lancewood,  chestnut  (smjll),  yew,  snakewood. 

Elasticity  and  toughness  :  Oak,  beech,  elm,  lignum-vitae,  walnut,  hornbeam. 

Even  Grain  (for  carving  and  engraving)  :  Pear,  pine,  box,  lime-tree. 

Durability  (in  dry  works)  :  Cedar,  oak,  yellow  pine,  chestnut. 

Building  (ship-building)  :  Cedar,  pine  (deal),  fir,  larch,  elm,  oak,  locust,  teak. 
Wet  construction  (as  piles,  foundations,  flumes,  etc.):  Elm,  alden,  beech,  oak, 
whitewood,  chestnut,  ash,  spruce,  sycamore. 

Machinery  and  Millwork  (frames):  Ash,  beech,  birch,  pine,  elm,  oak.  Rollers, 
etc. :  Box,  lignum-vitee,  mahogany.  Teeth  of  wheels  :  Crab-tree,  hornbeam, 
locust.    Foundry  patterns  :  Alden,  pine,  mahogany. 

Furniture  (common):  Beech,  birch,  cedar,  cherry,  pine,  whitewood.  Best 
furniture  :  Amboyna,  walnut,  oak,  rosewood,  satinwood,  sandalwood,  chestnut, 
cedar,  tulip-wood,  zebra-wood,  ebony. 

Of  these  varieties,  those  that  chiefly  enter  into  commerce  in  this  country  are 
oak,  hickory,  ash,  elm,  cedar,  black-walnut,  maple-cherry,  butternut,  etc. 

To  Measure  Grain  Bins. — A  cubical  box  I2|  inches  each  way  will  hold  a 
bushel.  Hence,  to  ascertain  the  contents  of  a  bin,  take  a  stick  or  rule  I2|  inches 
long,  and  divide  it  by  marks  into  tenths  and  hundredths.  Measure  the  length, 
breadth  and  depth  with  this  rule  ;  multiply  the  three  dimensions  together,  and 
the  product  will  be  bushels.  This  is  the  most  convenient  and  easiest  method 
known.  Use  the  rule  as  though  it  were  feet  and  inches.  Suppose,  for  example, 
a  bin  measures  8.5  in  length,  5.7  in  width,  and  4.9  in  depth.  The  product  of 
these  is  237.405,  or  about  237.4  bushels.  Every  farmer  should  make  such  a 
rule,  and  use  it  in  all  cases  where  the  contents  of  bins  or  boxes  are  required. 

It  is  a  common  thing,  when  a  screw  or  staple  becomes  loose,  to  draw  it  out, 
plug  up  the  hole  with  wood,  and  re-insert  it.  It  has  been  found  that  a  much 
better  way  is  to  fill  up  the  holes  tightly  with  cork.  Screws  and  irons  so  secured 
are  said  to  remain  perfectly  tight  as  long  as  when  put  into  new  wood. 

To  find  the  length  when  the  width  is  given,  to  contain  a  given  number  of 
square  feet.  For  example  :  required  the  length  of  a  piece  32  inches  wide,  to 
contain  8  square  feet.  8  X  1 2  =  9^  X  12  =  1 T52  -!-  32  —  3°  inches,  the 
length  required. 

A  weight  of  36,000  pounds  attached  to  a  bar  of  iron,  one  inch  square  and 
1,000  inches  in  length,  will  draw  it  out  one  inch  ;  45,000  pounds  will  stretch  it 
two  inches  ;  54,000  pounds,  four  inches  ;  63,000  pounds,  eight  inches,  and 
72,000  pounds,  sixteen  inches,  when  it  will  finally  break. 


40 


CARPENTRY. 


PLATE  21. 

Represents  the  geometrical  operation  of  finding  the  lines  re- 
quired for  the  sides  and  edges  of  pieces  placed  at  a  given  angle 
oblique  to  the  base. — To  butt  or  mitre  over  obtuse  and  acute 
angles. 

To  find  the  bevels  required  for  the  obtuse  angle,  F  G 
H,  Fig.  i.  Draw  the  base  A  B,  indefinitely.  Draw  C  D, 
the  angle  and  height  required.  To  find  the  angle,  to  cut 
the  face  of  the  piece  C  D  :  from  the  point  C  as  centre, 
with  C  D  as  radius,  describe  an  arc  cutting  the  base  at  R ; 
then  R  G  C  forms  the  angle  required.  To  find  the  angle 
to  cut  the  edge  of  the  piece :  from  the  point  H  as  centre, 
and  with  H  J  as  radius,  describe  an  arc ;  tangent  to  the 
arc,  and  parallel  to  N  J,  draw  the  dotted  line  to  intersect 
the  base  at  A  ;  join  A  G  and  N  F  ;  then  A  G  C  forms  the 
angle  required.  The  bevel  required  for  the  butt  joint  is 
given  at  A.  Join  A  G;  then  A  G  C  forms  the  angle 
required. 

The  operation  of  finding  the  bevels  for  the  acute-angled 
plan  at  Fig.  2  is  nearly  the  same,  and  consequently  needs 
no  explanation. 

These  rules  will  be  found  useful  to  workmen  in  con- 
structing boxes  where  the  sides  are  required  to  be  placed 
oblique  to  the  base.  Also  for  mitring  or  butting  purlins 
or  other  timbers  when  placed  in  similar  positions. 


7 


RULES.  4? 


Miscellaneous  Notes  &  Rules, 

The  greatest  force  produced  by  the  wind  on  a  vertical 
wall  is  equal  to  40  lbs.  to  the  square  foot. 

When  a  summer  or  beam  has  settled  one-fortieth  of  its 
length  it  is  liable  to  break. 

Laths  for  plastering  will  lay  48  feet  to  the  bundle,  equal 
to  53  square  yards. 

One  barrel  of  lime  to  one  cubic  yard  of  sand,  will  plas- 
ter 17  square  yards  with  two  coats. 

It  requires  14  bricks  to  lay  1  foot  in  length  and  1  foot 
in  height  of  an  8  inch  wall;  20  bricks  for  a  12  inch  wall, 
and  27  bricks  for  a  16  inch  wall. 

An  acre  of  ground  is  2083  feet  square,  and  contains 
43,560  square  feet. 

In  water,  sound  passes  4,766  feet  per  second  ;  in  air, 
1,146  feet  per  second. 

A  Winchester  bushel  is  183  inches  in  diameter,  8  inches 
deep,  and  contains  2,1505  cubic  inches. 

A  box  16X16  inches  square,  8J  inches  deep,  will  hold  a 
bushel. 

A  box  12X12  inches  square,  j\  inches  deep,  wiii  hold 
half  bushel. 

A  box  9X9  inches  square,  6\  inches  deep,  will  hold  one 
peck. 

A  box  7X7  inches  square,  si  inches  deep,  will  hold  4 
qts.,  or  half  peck. 

A  pile  of  wood  8  feet  long,  4  feet  wide  and  4  feet  high, 
contains  one  cord=to  128  cubic  feet. 

A  cistern  5  feet  diameter,  and  6  feet  deep,  will  hold  30 
barrels,  of  32  gallons  each. 

A  cistern  6  feet  diameter,  and  6  feet  deep,  will  hold  39 
barrels. 

A  cistern  7  feet  diameter,  and  6  feet  deep,  will  hold  54 
barrels. 


{Continued  on  page  49.) 


4H 


CARPENTRY. 


PLATE  22- 

FIGURE  i. — Represents  a  geometrical  demonstration  of 
finding  the  side  of  a  square,  the  area  of  which  shall  be  equal  to 
the  area  of  the  circle.  Also  to  find  the  side  of  a  cube,  the  con- 
tent of  which  shall  be  equal  to  the  content  of  a  globe,  or  ball, 
as  follows  : 

From  the  point  A  as  centre,  with  the  radius  of  the  cir- 
cle, describe  an  arc  cutting  the  circle  at  C  :  from  the  point 
C  as  centre,  with  C  D  as  radius,  describe  an  arc  cutting 
the  circle  at  E.  Draw  E  G  parallel  to  A  E,  and  G  S  at 
right  angles  to  A  B  ;  join  H  S,  the  side  required.  To 
find  the  side  of  a  cube  :  from  the  point  F  as  centre  describe 
an  arc  cutting  the  circle  at  L ;  join  H  L,  the  side 
required. 

Figures  2,  3. — Represent  the  plan  and  elevation  of  a 
box,  the  sides  of  which  are  placed  at  different  angles.  To 
find  the  face-bevel  for  the  side  5  L,  draw  2  E  equal  to  L 

5  :  from  the  point  2  as  centre,  describe  the  arc  E  T  ;  square 
over  from  T  to  N  ;  join  2  N,  the  angle  required.  The 
face-bevel  for  the  side  2  3  is  given  at  S,  The  bevel  re- 
quired to  miter  the  edges  is  drawn  at  P.  To  find  the 
angle  for  butt  joints,  draw  6  G  at  right  angles  to  2  H : 
from  the  points  6  and  G  as  centres,  describe  arcs  touching 
the  lines  2  3  and  2  E  ;  tangent  to  the  arcs,  draw  lines  from 

6  and  G,  intersecting  on  the  line  2  H,  forming  the  angle 
required.  The  bevel  to  be  applied  at  right  angles  to  the 
joint. 


RULES.  49 


At  the  depth  of  45  feet  the  temperature  of  the  earth  is 
uniform  throughout  the  year. 

Dimensions  of  drawings  for  patents  in  the  United 
States,  8.5x12  inches. 

The  lap  of  slates  varies  from  2  to  4  inches  ;  the  standard 
is  assumed  to  be  3  inches. 

The  pitch  of  a  slate  roof  should  not  be  less  than  1  inch 
in  height  to  4  inches  in  length. 

According  to  the  last  census,  there  are  2,000  Architects, 
350,000  Carpenters,  45,000  Cabinet  makers,  and  46,000 
Carriage  makers  in  the  United  States. 

The  strength  of  a  horse  is  equivalent  to  that  of  5  men  ; 
the  daily  allowance  of  water  for  a  horse  should  be  4  gal- 
lons. 

Elasticity  and  Strength. — The  component  parts  of 
a  rigid  body  adhere  to  each  other  with  a  force  which  is 
termed  cohesion. 

Elasticity  is  the  resistance  which  a  body  opposes  to  a 
change  of  form. 

Strength  is  the  resistance  which  a  body  opposes  to  a 
permanent  separation  of  its  parts. 

A  horse  can  draw  upon  a  plank  road  three  times  the 
load  that  he  can  upon  an  ordinary  broken  stone  or  macad- 
amized road. 


50 


CARPENTRY. 


PLATE  23. 

Exhibits  the  plan  and  elevation  of  the  angle  brackets  required 
for  internal  and  external  angles,  formed  with  a  cord  or  string. 

To  find  the  points  for  the  pins,  to  describe  the  elliptic 
curve  required  for  the  angle  bracket,  square  up  from  S  to 
H,  Fig.  1,  equal  to  B  D  :  from  the  point  H  as  centre,  with 
S  C  as  radius,  describe  arcs  cutting  the  major  axis  at  2 
and  3,  the  points  required. 

Figure  2. — Exhibits  the  plan  and  elevation  for  an  inter- 
nal angle  ;  the  elliptic  curve  of  the  bracket  is  found  in 
the  same  manner  as  Fig.  1. 

FIGURE  3. — Exhibits  a  geometrical  demonstration  of 
finding  the  centre  of  a  circle  when  lost.  Take  any  points, 
A,  C,  D,  equally  distant  from  each  other,  as  centres,  from 
which  describe  arcs  cutting  each  other ;  through  the 
points  of  intersection  draw  lines  to  intersect  at  J,  the 
point  required. 

To  erect  a  perpendicular  from  the  extremity  of-a  given 
line.  Draw  the  line  A  B,  Fig.  4.  To  find  the  perpendic- 
ular B  C  ;  from  any  point  D  as  centre,  with  D  B  as  radius, 
describe  an  arc,  cutting  the  given  line  at  A;  join  AD, 
and  extend  to  C  ;  join  B  C,  the  perpendicular  required. 


7 


Terms  Used  in  Carpentry. 

Abutment. — The  junction  or  meeting  of  two  pieces  of 
timber,  of  which  the  fibres  of  one  extend  perpendicular 
to  the  joint,  and  those  of  the  other,  parallel  to  it. 

Arris. — The  line  of  concourse  or  meeting-  of  two 
surfaces. 

Back  of  a  Hand-rail. — The  upper  side  of  it. 

Back  of  a  Hip. — The  upper  edge  of  a  rafter,  between 
the  two  sides  of  a  hipped  roof,  formed  to  an  angle,  so  as 
to  range  with  the  rafters  on  each  side  of  it. 

Back-Shutters  or  Back-Flaps. — Additional  breadths, 
hinged  to  the  front  shutters,  for  covering  the  aperture 
compieteiy  when  required  to  be  shut. 

Back  of  a  Window. — The  board,  or  wainscoting  be- 
tween the  sash-frame  and  the  floor,  uniting  with  the  two 
elbows,  and  forming  part  of  the  finish  of  a  room.  When 
framed,  it  has  commonly  a  single  panel,  with  mouldings 
on  the  framing,  corresponding  with  the  doors,  shutters, 
etc.,  in  the  apartment  in  which  it  is  fixed. 

Basil. — The  sloping  edge  of  a  chisel,  or  of  the  iron  of 
a  plane. 

Batten. — A  scantling  of  stuff  from  two  inches  to  seven 
inches  in  breadth,  and  from  half  an  inch  to  one  inch  and 
a  half  in  thickness. 

Baulk. — A  piece  of  fir  or  deal,  from  four  to  ten  inches 
square,  being  the  trunk  of  a  tree  of  that  species  of  wood, 
generally  brought  to  a  square  for  the  use  of  building. 

Bead. — A  round  moulding  commonly  made  upon  the 
edge  of  a  piece  of  stuff.  Of  beads  there  are  two  kinds; 
one  flush  with  the  surface,  called  a  quirk-bead,  and  the  other 
raised,  called  a  cock-bead. 

Beam. — A  horizontal  timber,  used  to  resist  a  force  or 
weight;  as  a  tie-beam,  where  it  acts  as  a  string  or  chain  by 
its  tension  ;  as  a  collar-beam,  where  it  acts  by  compression  ; 


Continued  on  page  53. 


52 


CARPENTRY. 


PLATE  24. 

Exhibits  rules  for  finding  a  section  of  the  raking  mould  to 
intersect  the  horizontal  moulding,  at  any  angle  of  elevation,  for 
right-angled  buildings.  Also  for  finding  a  section  of  the  raking 
moulding  for  the  table,  placed  at  any  intermediate  point,  diverg- 
ing from  the  straight  line  to  a  right  angle. 

To  find  a  section  of  the  raking  moulding  to  intersect  the 
horizontal  moulding  for  right-angled  buildings.  At  Fig. 
i,  the  plan  and  elevation  of  the  gable  are  given.  Also  the 
horizontal  and  raking  moulds  required  to  intersect  each 
other  when  in  position.  The  rules  for  drawing  and  trans- 
ferring the  distances  to  form  the  raking  moulding  at  B 
Fig.  i,  are  simple  geometrical  operations  which  the  work 
man  will  find  no  difficulty  in  comprehending. 

To  find  the  raking  mould  for  the  gable  placed  on  the 
diverging  lines  i,  2,  3,  etc.  Produce  B  S  to  C  equal  to  S 
E.  Divide  the  quadrant  F  H  into  any  number  of  parts. 
Extend  the  line  D  F,  Fig.  ir  to  G,  equal  to  the  develop- 
ment of  the  arc  F  H.  Produce  the  lines  E  S  and  G  H,  to 
intersect  each  other:  from  the  point  of  intersection  draw 
the  radiating  lines  11,  22,  etc.;  join  GE:  parallel  to  GE, 
di~aw  lines  from  the  points  1,  2,  3,  etc.,  to  intersect  the  line 
EF:  from  the  points  of  intersection,  draw  lines  parallel  to 
E  D,  cutting  the  line  F  D  at  the  points  1,  2,  3,  etc.;  join  S  1, 
S  2,  etc.  Then  the  line  S  1  is  the  angle  of  elevation  from 
which  to  draw  the  raking  mould  for  the  gable  S  D  E, 
Fig.  1,  placed  on  the  diverging  line  S  J,  Fig.  2.  The 
angle  of  elevation  from  which  to  draw  the  raking  mould 
for  the  gable  S  D  E,  placed  on  any  of  the  diverging  lines, 
is  found  at  the  corresponding  figures  on  the  line  F  D,. 
Fig.  1. 

Note. — If  the  horizontal  moulding  were  continued  in  the  straight  line  S 
H,  though  elevated  to  the  angle  of  the  gable,  it  would  not  require  a  change 
of  form.  But  if  the  elevated  line  were  to  diverge  from  the  straight  line, 
it  would  begin  to  form  the  right  angle,  and  consequently  commence  to 
chnnge  its  form  from  the  horizontal  to  the  raking  mould  required  for  the  right 
angle. 

Figure  3. — To  find  a  veneer  for  a  Gothic  head-jamb 
splayed  alike  all  around.  Produce  the  splay  from  B  to  A, 
the  radius  to  describe  the  veneer  required  to  cover  the 
circular  jamb. 


TERMS  USED  IN  CARPENTRY.  53 


as  a  bressicmmer,  where  it  resists  a  transverse  insisting 
weight. 

Bearer. — Anything  used  by  way  of  support  to  another. 

Bearing. — The  dr-tance  in  which  a  beam  or  rafter  is 
suspended  in  the  clear ;  thus,  if  a  piece  of  timber  rests 
upon  two  opposite  walls,  the  span  of  the  void  is  called  the 
bearing,  and  not  the  whole  length  of  the  timber. 

Bench. — A  platform  supported  on  four  legs,  and  used 
for  planing  upon,  etc. 

Bevel. — One  side  is  said  to  be  bevelled  with  respect  to 
another,  when  the  angle  formed  by  these  two  sides  is 
greater  or  less  than  a  right  angle. 

Bird's  Mouth. — An  interior  angle,  formed  on  the  end 
of  a  piece  of  timber,  so  that  it  may  rest  firmly  upon  the 
exterior  angle  of  another  piece. 

Blade. — Any  part  of  a  tool  that  is  broad  and  thin  ;  as 
the  blade  of  an  axe,  of  an  adze,  of  a  chisel,  etc.;  but  the 
blade  of  a  saw  is  generally  called  a  plate. 

Blockings. — Small  pieces  of  wood,  fitted  in,  or  glued, 
•or  fixed,  to  the  interior  angle  of  two  boards  or  other 
pieces,  in  order  to  give  strength  to  the  joint. 

Board. — A  substance  of  wood  contained  between  two 
parallel  planes  ;  as  when  the  baulk  is  divided  into  several 
pieces  by  the  pit  saw,  the  pieces  are  called  boards.  The 
•section  of  boards  is  sometimes,  however,  of  a  triangular, 
or  rather  trapezoidal,  form  ;  that  is,  with  one  edge  very 
thin  ;  these  are  called  feather-edged  boards. 

Bond-Timbers. —  Horizontal  pieces,  built  in  stone  or 
brick  walls,  for  strengthening  them,  and  securing  the  bat- 
tening, lath,  plaster,  etc. 

Bottom  Rail. — The  lowest  rail  of  a  door. 

Boxings  of  a  Window. — The  two  cases,  one  on  each 
side  of  a  window,  into  which  the  shutters  are  folded. 

Brace. — A  piece  of  slanting  timber,  used  in  truss-par- 
titions, or  in  framed  roofs,  in  order  to  form  a  triangle,  and 
thereby  rendering  the  frame  immovable  ;  when  a  brace 
is  used  by  way  of  support  to  a  rafter,  it  is  called  a  strut. 


[Continued  on  page  55.) 


54 


CARPENTRY. 


PLATE  25. 

Exhibits  rules  for  finding  the  lines  to  cut  the  sides  and 
edges  of  a  piece  placed  at  a  given  angle  oblique  to  the  base. — 
To  miter  over  right,  acute  and  obtuse  angles. 

Draw  the  acute  angle  ABC,  Fig.  i  ;  join  B  D,  the  line 
of  intersection ;  draw  I  J,  the  pitch  required.  At  right 
angles  to  I  J  draw  I  A;  from  the  point  I  as  centre,  with  I  J 
and  I  A  as  radii,  describe  the  arcs  J  K  and  AG;  tangent 
to  the  arcs,  draw  lines  parallel  to  A  B,  indefinitely  ;  from 
the  point  B  draw  a  line  at  right  angles  to  A  B,  cutting 
the  tangents  in  L  and  H  ;  join  L  D  and  H  D,  the  angles 
required.  The  bevel  for  the  sides  of  the  piece  is  shown 
at  H  ;  for  the  edges  of  the  piece,  at  L. 

Figures  2  and  3  are  examples  of  obtuse  and  right-angled 
figures;  the  operation  of  finding  the  angles  for  the  bevels 
is  the  same.  Fig.  4  represents  the  rule  for  finding  the 
lines  for  a  butt  joint.  The  bevel  to  be  applied  at  right 
angles  to  the  lines  on  the  sides  of  the  piece. 


TERMS  USED  IN  CARPENTRY.  55 


Braces,  in  partitions  and  spanroofs,  are  always,  or  should 
be,  disposed  in  pairs  and  placed  in  opposite  directions. 

Brace  and  Bits. — The  same  as  stock  and  bits,  as  ex- 
plained hereafter. 

Brad. — A  small  nail,  having  no  head  except  on  one 
edge.  The  intention  is  to  drive  it  within  the  surface  of 
the  wood  by  means  of  a  hammer  and  punch,  and  to  fill 
the  cavity  flush  to  the  surface  with  putty. 

Breaking  Down,  in  sawing,  is  dividing  the  baulk  into 
boards  or  planks ;  but,  if  planks  are  sawed  longitudinally, 
through  their  thickness,  the  saw-way  is  called  a  ripping-cut 
and  the  former  a  breaking-cut. 

To  Break-in. — To  cut  or  break  a  hole  in  brick-work, 
with  the  ripping  chisel,  for  inserting  timber,  etc. 

Breaking  Joint. — Is  the  joint  formed  by  the  meeting 
of  several  heading  joints  in  one  continued  line,  which  is 
sometimes  the  case  in  folded  doors. 

Bressummer  or  Breastsummer.— A  beam  supporting 
a  superincumbent  part  of  an  exterior  wall,  and  running 
longitudinally  below  that  part. — See  Summer. 

Bridged  Gutters. — Gutters  made  with  boards  sup- 
ported below  with  bearers,  and  covered  over  with  lead. 

Bridging  Floors. — Floors  in  which  bridging  joists  are 
used. 

Bridging  Joists. — The  smallest  joints  in  naked  floor- 
ing, for  supporting  the  boarding  for  walking  upon. 

Butting  Joint. — The  junction  formed  by  the  surfaces 
of  twro  pieces  of  wood,  of  which  one  surface  is  perpen- 
dicular to  the  fibres,  and  the  other  in  their  direction,  or 
making  with  them  an  oblique  angle. 

Chamber. — The  convexity  of  a  beam  upon  the  upper 
edge,  in  order  to  prevent  its  becoming  straight  or  con- 
cave by  its  own  weight,  or  by  the  burden  it  may  have  to 
sustain,  in  course  of  time. 

Chamber  Beams. — Those  beams  used  in  the  flats  of 
truncated  roots,  and  raised  in  the  middle  with  an  obtuse 
angle,  for  discharging  the  rain-water  towards  both  sides 
of  the  roof. 

(Continued  on  page  57.) 


56 


CARPENTRY. 


PLATE  26. 

FIGURE  i. — Represents  the  geometrical  operation  of  finding 
the  curve  and  length  of  the  body  or  side  of  a  circular  pan. 
Also  the  side  of  a  square  pail  the  content  of  which  shall  be 
equal  to  the  content  of  the  circular  pan. 

To  find  the  side  of  a  square  pan.  From  the  point  F 
as  centre,  with  the  radius  of  the  circle,  describe  an  arc 
cutting  the  circle  at  H:  from  the  point  H  as  centre,  with 
H  S  as  radius,  describe  an  arc  cutting-  the  circle  at  J  : 
draw  J  R  parallel  to  D  F,  and  R  P  at  right  angles  to 
G  F  ;  join  G  P,  the  side  required.  The  angle  for  the  joints 
is  given  at  A. 

To  find  the  curve  required  for  the  body  of  the  circular 
pan,  produce  the  sides  C  A  and  D  B  to  intersect  at  E: 
from  the  point  of  intersection,  describe  arcs  from  D  and 
B,  indefinitely.  To  find  the  length  of  the  body,  join  P  L: 
then  from  the  point  D  as  centre,  with  P  L  as  radius, 
describe  an  arc  cutting  the  curve  at  N,  one-fourth  of  the 
length  required.* 

Figure  2. — Represents  three  circles,  and  three  inscribed 
squares.  The  second  square  equals  half  the  area  of  the 
first ;  the  third  square  equals  one-fourth  the  area  of  the 
first  square.  The  same  rule  applies  to  the  circles.  An 
inspection  of  the  figure  is  sufficient  for  its  comprehension. 

Figure  3. — Shows  a  practical  rule  for  finding  the  bevels 
for  mitering  pieces  placed  oblique  to  the  base. 

Draw  A  B,  the  angle  required  ;  at  right  angles  to  A  B, 
draw  B  C :  from  the  points  A  and  C  as  centres,  describe 
the  arcs  B  D  and  B  E ;  tangent  to  the  arcs,  draw  D  S 
and  E  H  ;  join  A  S  and  C  H.  The  bevel  for  the  face 
A  B  is  shown  at  S  ;  the  bevel  for  the  edge  is  shown  at  H. 
If  butt  joints  at  the  angles  are  required,  join  A  H  for  the 
bevel  at  A. 


*  Add  all  necessary  material  for  edges  and  seams. 


TERMS  USED  IN  CARPENTRY.  57 


Cantalevers. — Horizontal  rows  of  timber,  projecting 
at  right  angles  from  the  naked  part  ot  a  wall,  for  sustain- 
ing the  eaves  or  other  mouldings.  Sometimes  they  are 
planed  on  the  horizontal  and  vertical  sides,  and  sometimes 
the  carpentry  is  rough  and  cased  with  joinery. 

Carriage  of  a  Stair. — The  timber-work  which  sup- 
ports the  steps. 

Carcase  of  a  Building. — The  naked  walls  and  the 
rough  timber-work  of  the  flooring  and  quarter  partitions, 
before  the  building  is  plastered  or  the  floors  laid. 

Carry-up. — A  term  used  among  builders  or  workmen, 
denoting  that  the  walls  or  other  parts,  are  intended  to  be 
built  to  i  certain  given  height:  thus,  the  carpenter  will 
say  to  the  brick-layer,  Carry-up  that  wall ;  carry-up  that 
stack  of  chimneys ;  which  means,  build  up  that  wall  or  stack 
of  chimneys. 

Casting  or  warping. — The  bending  of  the  surfaces  of 
a  piece  of  wood  from  their  original  position,  either  by  the 
weight  of  the  wood,  or  by  an  unequal  exposure  to  the 
weather  or  by  an  unequal  texture  of  the  wood. 

Chamfering. — Cutting  the  edge  of  any  thing,  origi- 
nally right-angled,  aslope  or  bevelled. 

Clamp. — A  piece  of  wood  fixed  to  the  end  of  a  thin 
board,  by  mortise  and  tenon,  or  by  groove  and  tongue,  so 
that  the  fibres  of  the  one  piece,  thus  fixed,  traverse  those 
of  the  board,  and  by  this  means  prevent  it  from  casting  : 
the  piece  at  the  end  is  called  a  clamp,  and  the  board  is  said 
to  be  clamped. 

Clear  Story  Windows  are  those  that  have  no 
transom. 

Cross-Grained  Stuff  is  that  which  has  its  fibres  run- 
ning in  contrary  positions  to  the  surfaces  ;  and,  conse- 
quently, cannot  be  made  perfectly  smooth,  when  planed 
in  one  direction,  without  turning  it  or  turning  the  plane, 

Crown-Post— The  middle  post  of  a  trussed  roof.— See 
King-Post. 

{Continued on  page  59.) 


58 


CARPENTRY. 


PLATE  27. 

Exhibits  the  plan  and  elevation  of  a  circular  desk.  Also 
the  plan  and  elevation  of  a  circular  seat. 

Figures  i,  2. — Represent  the  plan  and  elevation  of  the 
circular  desk.  To  find  the  radii  of  the  arcs  required  for 
the  ribs  to  form  the  drum,  to  bend  the  circular  inclining 
top,  A  B  C  D,  Fig.  2.  Draw  G  H,  the  angle  shown  on  the 
elevation,  Fig.  1.  Square  over  from  I  to  L ;  also  from 
H  to  M.  From  the  points  L  and  M  as  centres,  describe 
arcs  touching  the  line  G  H  ;  tangent  to  the  arcs,  and  at 
right  angles  to  GH,  draw  N  J  and  R  K,  the  radii 
required.  To  find  the  centres  from  which  to  describe 
the  ribs.  From  the  points  A  and  B  as  centres,  with  R  K 
as  radius,  describe  arcs  cutting  each  other  at  P,  the 
centre  required  ;  from  which  describe  the  arc  A  S  B  for 
the  rib  placed  over  the  chord  A  B.  The  rib  placed  over 
the  chord  C  D  is  found  in  the  same  manner.  The  ribs  wilL 
require  beveling  at  the  points  of  contact,  A,  B. 

Figure  3. — Represents  the  piece  required  for  the  cir- 
cular inclining  top.  The  radii  to  describe  the  outside  and 
inside  curves  are  taken  from  G  I  and  G  H,  Fig.  2.  The 
radiated  lines  shown  on  the  piece  are  grooves  for  the 
keys  required  to  shape  the  piece. 

Figures  4,  5. — Exhibit  the  plan  and  elevation  of  a 
circular  seat  with  an  inclining  back.  The  rules  for  find- 
ing the  radii  to  describe  the  seat  and  back  pieces,  placed 
parallel  to  each  other  when  in  position,  are  the  same  as 
those  used  for  finding  the  veneer  for  a  Gothic  head-jamb* 
splayed  alike  all  around. 


/ 


TERMS  USED  IN  CARPENTRY.  5$ 


Curling  Stuff. — That  which  is  occasioned  by  the 
winding  or  coiling-  of  the  fibres  round  the  boughs  of  the 
tree,  when  they  begin  to  shoot  from  the  trunk. 

Deal  Timber. — The  timber  of  the  fir  tree,  as  cut  into 
boards,  planks,  etc.,  for  the  use  of  building. 

Discharge. — A  post  trimmed  up  under  a  beam,  or  part 
of  a  building  which  is  weak  or  overcharged  by  weight. 

Door-Frame. — The  surrounding  case  of  a  door,  into 
which,  and  out  of  which,  the  door  shuts  and  opens. 

Dormer,  or  Dormer  Window. — A  projecting  window 
in  the  roof  of  a  house ;  the  glass  frame,  or  casements,  be- 
ing set  vertically,  and  not  in  the  inclined  sides  of  the  roofs  : 
thus  dormers  are  distinguished  from  skylights,  which  have 
their  sides  inclined  to  the  horizon. 

Drag. — A  door  is  said  to  drag  when  it  rubs  on  the 
floor.  This  arises  from  the  loosening  of  the  hinges,  or  the 
settling  of  the  building. 

Dragon-Beam. — The  piece  of  timber  which  supports 
the  hip-rafter,  and  bisects  the  angle  formed  by  the  wall- 
plates. 

Dragon-Piece. — A  beam  bisecting  the  wall-plate,  for 
receiving  the  heel  or  foot  of  the  hip-rafters. 

Edging. —  Reducing  the  edges  of  ribs  or  rafters,  exter* 
nally  or  internally,  so  as  to  range  in  a  plane,  or  in  any 
curved  surface  required. 

Enter. — When  the  end  of  a  tenon  is  put  into  a  mortise, 
it  is  said  to  enter  the  mortise. 

Face-Mould. — A  mould  for  drawing  the  proper  figure 
of  a  hand-rail  on  both  sides  of  the  plank ;  so  that  when 
cut  by  a  saw,  held  at  a  required  inclination,  the  two  sur- 
faces of  the  rail-piece,  when  laid  in  the  right  position,  will 
be  everywhere  perpendicular  to  the  plan. 

Fang. — The  narrow  part  of  the  iron  of  any  instrument 
which  passes  into  the  stock. 

Feather-edged  Boards.— Boards,  thicker  at  one  edge 
than  the  other,  and  commonly  used  in  the  facing  of 
wooden  walls,  and  for  the  covering  of  inclined  roofs,  etc. 

(Continued  on  page  61.) 


60 


CARPENTRY. 


PLATE  28. 

Exhibits  the  operation  of  finding  the  angle  rafter  for  French 
Roofs. 

The  plan  and  elevation  of  the  common  raftefs  are  shown 
at  Figs,  i  and  2.  To  find  the  major  and  minor  axes  of  the 
elliptic  curve  required  for  the  angle  rafter  A  B,  Fig.  r. 
Draw  A  D  at  right  angles  to  A  B,  equal  to  S  H,  Fig.  2; 
from  the  point  D  draw  a  line  parallel  to  A  B,  indefinitely. 
Through  the  point  P  draw  C  R  parallel  to  D  A,  equal  to 
P  B  ;  then  C  D  equals  half  of  the  major  axis,  and  C  R  equals 
half  of  the  minor  axis,  of  the  elliptic  curve  required.  To 
find  the  points  for  the  pins,  to  describe  the  elliptic  curve: 
from  the  point  R  as  centre,  with  C  D  as  radius,  describe 
arcs  cutting  the  major  axis  at  2  and  3,  the  points  required. 
To  form  the  angle  rafter  by  ordinates,  draw  any  number, 
11,  22,  etc. ;  transfer  the  distances,  and  through  the  points 
trace  the  elliptic  curve  required. 

Figure  3. — Represents  a  simple  and  easy  rule  for  find- 
ing the  section  of  a  semi-cylinder  cut  at  a  given  angle 
oblique  to  the  base.  From  the  points  A,  B,  C,  on  the 
plan,  draw  lines  at  right  angles  to  A  C,  indefinitely. 
Draw  D  E,  the  angle  required  ;  also  the  oblique  angle 
C  F.  To  find  the  direction  of  the  major  axis,  set  off  from 
1  to  2,  equal  to  3,4;  from  the  point  2  square  up  to  5, 
equal  to  3  B  ;  join  1,  5,  the  minor  axis;  through  the  point 
1  draw  the  major  axis  at  right  angles  to  1,  5,  indefinitely. 
To  find  the  points  for  the  pins,  to  describe  the  semi- 
ellipse:  from  the  point  5  as  centre,  with  1  D  as  radius, 
describe  arcs  cutting  the  major  axis  at  6  and  7,  the  points 
required. 


/ 


TERMS  USED  IN  CARPENTRY.  61 


Fence  of  a  Plane. — A  guard  which  obliges  it  to  work 
to  a  certain  horizontal  breadth  from  the  arris. 

Filling-in  Pieces. — Short  timbers  less  than  the  full 
length  ;  as  the  jack-rafters  of  a  roof,  the  puncheons  or 
short  quarters,  in  partitions,  between  braces  and  sills,  or 
head  pieces. 

Fine-set. — A  plane  is  said  to  be  fine-set,  when  the 
sole  of  the  plane  so  projects  as  to  take  a  very  thin  broad 
shaving. 

Fir  Poles. — Small  trunks  of  fir  trees,  from  ten  to  six- 
teen feet  in  length,  used  in  rustic  buildings  and  out- 
houses. 

Free  Stuff. — That  timber  or  stuff  which  is  quite  clean, 
or  without  knots,  and  works  easily  without  tearing. 

Frowy  Siuff. — The  same  as  free  stuff. 

Furrings. — Slips  of  timber  nailed  to  joists  or  rafters, 
in  order  to  bring  them  to  a  level,  and  to  range  them  into 
a  straight  surface,  when  the  timbers  are  sagged,  either  by 
casting,  or  by  a  set  which  they  have  obtained  by  their 
weight,  in  length  of  time. 

Girder. — The  principal  beam  in  a  floor  for  supporting 
the  binding  joists. 

Glue. — A  tenacious  viscid  matter,  which  is  used  as  a 
cement,  by  carpenters,  joiners,  etc. 

Grind-Stone. — A  cylindrical  stone,  by  which,  on  its 
being  turned  round  its  axis,  edge-tools  are  sharpened,  by 
applying  the  basil  to  the  convex  surface. 

Ground-Plate  or  Sill. — The  lowest  plate  of  a  wood- 
en building  for  supporting  the  principal  and  other  posts. 

Grounds. — Pieces  of  wood  concealed  in  a  wall,  to 
which  the  facings  or  finishings  are  attached,  and  having 
their  surfaces  flush  with  the  plaster. 

Handspike. —  A  lever  for  carrying  a  beam,  or  other 
body,  the  weights  being  placed  in  the  middle,  and  sup- 
ported at  each  end  by  a  man. 

Hanging  Stile. — The  stile  of  a  door  or  shutter  to 
which  the  hinge  is  fastened  ;  also,  a  narrow  stile  fixed  to 
the  jamb  on  which  a  door  or  shutter  is  frequently  hung. 
{Continued  on  page  63.) 


C2 


carpentry 


PLATE  29. 

Mitring  of  Circular  Mouldings. 

Some  twenty  years  have  elapsed  since  I  first  published 
the  House  Carpenter's  Assistant,  in  which  rules  were 
given  for  the  mitring-  of  circular  mouldings.  The  idea,  I 
think,  originated  with  me.  It  being  seldom  that  the  work- 
man is  required  to  perform  the  operation  of  mitring  cir- 
cular mouldings,  yet  if  he  ever  should  be,  a  knowledge  of 
the  rules  here  given  will  make  it  an  agreeable  occupation 
rather  than  an  unpleasant  task  attended  with  anxiety  and 
uncertainty. 

Figure  i. — Represents  the  rule  for  finding  the  centres, 
from  which  to  describe  the  intersecting  line,  and  is  appli- 
cable to  all  cases. 

Figure  4. — Shows  how  nearly  impossible  it  is  to  accu- 
rately perform  work  of  this  kind,  without  the  use  of  the 
compasses  for  describing  the  intersecting  lines. 


/ 


TERMS  USED  IN  CARPENTRY.  63 


Hip-Roof. — A  roof  the  ends  of  which  rise  immediately 
from  the  wall-plate,  with  the  same  inclination  to  the  hori- 
zon, and  its  other  two  sides.  The  Backing  of  a  Hip  is  the 
angle  made  on  its  upper  edge  to  the  range  with  the  two 
sides  or  planes  of  the  roof  between  which  it  is  placed. 

Hoarding. — An  enclosure  of  wood  about  a  building, 
while  erecting  or  repairing. 

Jack-Rafters. — All  those  short  rafters  which  meet  the 
hips. 

Jack  Ribs. — Those  short  ribs  which  meet  the  angle 
ribs,  as  in  groins,  domes,  etc. 

Jack  Timber. — A  timber  shorter  than  the  whole  length 
of  other  pieces  in  the  same  range. 

Inter-tie  or  Enter-tie. — A  horizontal  piece  of  timber, 
framed  between  two  posts,  in  order  to  tie  them  together. 

Joggle-Piece. — A  truss  post,  with  shoulders  and 
sockets  for  abutting  and  fixing  the  lower  ends  of  the 
struts. 

Joists.  —Those  beams  in  a  floor  which  support,  or  are 
necessary  in  the  supporting  of,  the  boarding  or  ceiling  ; 
as  the  binding,  bridging  and  ceiling  joists ;  girders  are, 
however,  to  be  excepted,  as  not  being  joists. 

Juffers. — Stuff  of  about  four  or  five  inches  square,  and 
of  several  lengths.  This  term  is  out  of  use,  though  fre- 
quently found  in  old  books. 

Kerf. — The  way  which  a  saw  makes  in  dividing  a  piece 
of  wood  into  two  parts. 

King-Post. — The  middle  post  of  a  trussed  roof,  for 
supporting  the  tie-beam  at  the  middle  and  the  lower  ends 
of  the  struts. 

Knee. — A  piece  of  timber  cut  at  an  angle,  or  having 
grooves  to  an  angle.  In  hand-railing  a  knee  is  part  of  the 
back,  with  a  convex  curvature,  and  therefore  the  reverse 
of  a  ramp,  which  is  hollow  on  the  back,  now  called  over 
or  under  easing. 

Knot. — That  part  of  a  piece  of  timber  where  a  branch 
had  issued  out  of  the  trunk. 


{Continued  on  page  65.) 


64 


CARPENTRY. 


PLATE  30. 

The  designs  drawn  in  this  plate  are  given  to  show  what 
can  be  done  with  the  saw,  a  few  chisels  and  the  plough^ 
which  are  all  the  tools  required  to  construct  the  sash. 
Although  the  bead  and  rosette,  placed  in  the  panels,  will 
add  very  much  to  the  appearance  of  the  door,  the  work- 
man requires  no  sash  tools  to  construct  the  sash,  or  mould- 
ing planes  for  the  door,  such  as  are  necessary  to  make  the 
common  paneled  doors  and  sash  now  in  general  use.  The 
sash  need  not  be  over  one  and  one-fourth  inches  in  thick- 
ness. The  splays  can  be  tinted,  and  when  done  by  an 
artistic  painter,  present  both  taste  and  style  in  the  design  ; 
to  add  to  which,  the  door  may  be  tinted  and  shaded  in 
three  or  four  colors.  The  designs  here  given  can  be  seen 
in  the  building  now  occupied  by  the  author  in  Newark, 
N.  J. 


TERMS  USED  IN  CARPENTRY.  65 


Lining  of  a  Wall. — A  timber  boarding-,  of  which  the 
edges  are  either  rebated  or  grooved  and  tongued. 

Lintels. — Short  beams  over  the  heads  of  doors  and 
windows,  for  supporting  the  inside  of  an  exterior  wall ; 
and  the  super-incumbent  part  over  doors,  in  brick  or 
stone  partitions. 

Lower  Rail. — The  rail  at  the  foot  of  a  door  next  to 
the  floor. 

Lying  Panel. — A  panel  with  the  fibres  of  the  wood  dis- 
posed horizontally. 

Margins  or  Margents. — The  flat  part  of  the  stiles  and 
rails  of  framed  work. 

Middle  Rail. — The  rail  of  a  door  which  is  upon  a 
level  with  the  hand  when  hanging  freely  and  bending  the 
joint  of  the  wrist.  The  lock  of  the  door  is  generally  fixed 
in  this  rail. 

Mitre. — If  two  pieces  of  wood  be  formed  to  equal  an- 
gles, or  if  the  two  sides  of  each  piece  form  an  equal  in- 
clination, and  two  sides,  one  of  each  piece,  be  joined  to- 
gether at  their  common  vertex  so  as  to  make  an  angle,  or 
an  inclination  double  that  of  either  piece,  they  are  said  to 
be  mitred  together,  and  the  joint  is  called  the  viitre. 

Mortise  and  Tenon. — The  tenon,  in  general,  may  be 
taken  at  about  one-third  of  the  thickness  of  the  stuff. 

When  the  mortise  and  tenon  are  to  lie  horizontally,  as 
the  juncture  will  thus  be  unsupported,  the  tenon  should 
not  be  more  than  one-fifth  of  the  thickness  of  the  stuff;  in 
order  that  the  strain  on  the  upper  surface  of  the  tenoned 
piece  may  not  split  off  the  under  cheek  of  the  mortise. 

When  the  piece  that  is  tenoned  is  not  to  pass  the  end 
of  the  mortised  piece,  the  tenon  should  be  reduced  one- 
third  or  one-fourth  of  its  breadth,  to  prevent  the  necessity 
of  opening  one  side  of  the  tenon.  As  there  is  always 
some  danger  of  splitting  the  end  of  the  piece  in  which 
the  mortise  is  made,  the  end  beyond  the  mortise  should, 
as  often  as  possible,  be  made  considerably  longer  than  it 
is  intended  to  remain  ;  so  that  the  tenon  may  be  driven 
tightly  in,  and  the  superfluous  wood  cut  off  afterwards. 

{Continued  on  page  67.) 


ORNAMENTAL  WORK. 


PLATE  31. 

Exhibits  the  method  of  constructing  a  Corinthian  truss. 

A  represents  the  eye  of  its  volute  at  large,  with  the 
centres  numbered  on  which  the  curves  are  described.  B 
and  C  are  geometrical  views  showing  the  front  and  side 
elevation.  A  careful  inspection  of  which  will  enable  the 
workman  to  construct  one  of  any  size  he  may  require. 


PLASTERER'S  WORK. 

The  measuring  and  valuation  of  plasterer's  work  is  con- 
ducted by  surveyors.  All  common  plastering  is  measured 
by  the  yard  square,  of  nine  feet ;  this  includes  the  par- 
titions and  ceilings  of  rooms,  stuccoing,  internally  and 
externally,  etc.,  etc.  Cornices  are  measured  by  the  foot 
superficial,  girting  their  members  to  ascertain  their  widths, 
which  multiplied  by  their  lengths,  will  produce  the  super- 
ficial contents.  Running  measures  consist  of  beads,  quirks, 
arrises,  and  small  mouldings.  Ornamental  cornices  are 
frequently  valued  in  this  way  ;  that  is,  by  the  running  foot. 

The  labor  in  plasterer's  work  is  frequently  of  more  con- 
sideration than  the  materials  ;  hence  it  becomes  requisite 
to  note  down  the  exact  time  which  is  consumed  in  effect- 
ing particular  portions,  so  that  an  adequate  and  proper 
value  may  be  put  upon  the  work. 


! 

TERMS  USED  IN  CARPENTRY.  67 


But  the  above  regulations  may  be  varied,  according  as 
the  tenoned  or  mortised  piece  is  weaker  or  stronger. 

The  labor  of  making  deep  mortises,  in  hard  wood,  may 
be  lessened,  by  first  boring  a  number  of  holes  with  the 
auger  in  the  part  to  be  mortised,  as  the  compartments  be- 
tween may  then  more  easily  be  cut  away  by  the  chisel. 

Before  employing  the  saw  to  cut  the  shoulder  of  a 
tenon,  in  neat  work,  if  the  line  of  its  entrance  be  correctly 
determined  by  nicking  the  place  with  a  paring  chisel, 
there  will  be  no  danger  of  the  wood  being  torn  at  the 
edges  by  the  saw. 

As  the  neatness  and  durability  of  a  juncture  depend 
entirely  on  the  sides  of  the  mortise  coming  exactly  in  con- 
tact with  the  sides  of  the  tenon ;  and,  as  this  is  not  easily 
performed  when  a  mortise  is  to  pass  entirely  through  a 
piece  of  stuff,  the  space  allotted  for  it  should  be  first  of  all 
correctly  gauged  on  both  sides.  One  half  is  then  to  be 
cut  from  one  side,  and  the  other  half  from  the  opposite 
side  ;  and  as  any  irregularities,  which  may  arise  from  an 
error  in  the  direction  of  the  chisel,  will  thus  be  confined 
to  the  middle  of  the  mortise,  they  will  be  of  very  little 
hindrance  to  the  exact  fitting  of  the  sides  of  the  mortise 
and  tenon.  Moreover,  as  the  tenon  is  expanded  by  wedges 
after  it  is  driven  in,  the  sides  of  the  mortise  may,  in  a 
small  degree,  be  inclined  towards  each  other,  near  the 
shoulders  of  the  tenon. 

Mullion  OR  Munnion. — A  large  vertical  bar  of  a  win- 
dow frame,  separating  two  casements,  or  glass-frames,  from 
each  other. 

Vertical  mullions  are  called  munnions ;  and  those  which 
extend  horizontally  are  transoms. 

Muntins  OR  MONTANTS. — The  vertical  pieces  of  the 
frame  of  a  door  between  the  stiles. 

Naked  Flooring.— The  timber-work  of  a  floor  for  sup- 
porting the  boarding  or  ceiling,  or  both. 

Newel.— The  post,  in  a  dog-legged  stairs,  where  the 
winders  terminate,  and  to  which  the  adjacent  string-boards 
are  fixed, 

{Continued  on  page  69.) 


STAIRS. 


PLATE  32- 

To  build  stairs,  the  workman  will  first  get  the  size  ot 
the  room  and  the  height  of  the  story  which  determines 
the  width  of  the  steps  and  risers  ;  the  length  of  which 
and  the  size  of  the  opening  are  a  matter  of  taste  or  con- 
venience.  The  cylinder  is  staved  up  and  secured  with 
glue  and  screws.  The  string  pieces  are  secured  to  the 
cylinder  in  the  same  manner. 

To  find  the  development  or  stretchout  of  the  cylinder,. 
Fig.  i,  describe  the  arcs  2,  3,  and  4,  5  ;  from  the  point  5,. 
draw  the  diagonal  5,  7,  at  an  angle  of  450;  then  7,  8,  equals 
one-half  of  the  semi-circle  that  forms  the  cylinder  ;  set 
off  from  2  to  A  and  B  equal  to  7,  8 ;  draw  the  elevation 
of  the  steps  and  risers,  Fig.  2,  below  and  above  the  plat- 
form. Then  the  front  string-piece  should  be  wide  enough 
to  receive  suitable  width  of  timber  to  support  the  stairs. 
Form  the  easing  on  the  stretchout  of  the  cylinder,  which 
completes  the  elevation  for  a  platform  stairs. 

Figure  3. — Is  an  elevation  of  the  cylinder  and  easing 
for  a  straight  flight  of  stairs.  The  back  string-piece 
should  be  mortised  about  y%  of  an  inch  deep,  and  large 
enough  to  receive  wedges,  glued,  to  secure  the  steps  and 
risers. 

The  workman  should  in  all  cases  imagine  that  he  sees 
what  he  wants  and  can  do  it ;  now  suppose  we  place  the 
centre  of  the  cylinder,  Fig.  2,  over  the  centre  of  the  plan, 
then  bring  the  lower  and  upper  ends  of  the  string-pieces 
around  until  the  lines  from  A  and  B  stand  over  the  points 
9  and  8,  and  the  steps  correspond  with  the  steps  on  the 
plan,  which  will  be  the  case  if  executed  according  to  the 
drawings. 


TERMS  USED  IN  CA  R  TEN  TRY.  60 


Ogee. — A  moulding-,  the  transverse  section  of  which 
consists  of  two  curves  of  contrary  flexure. 

Panel. — A  thin  board  having  all  its  edges  inserted  in 
the  groove  of  a  surrounding  frame. 

Pitch  of  a  Roof. — The  inclination  which  the  sloping 
sides  make  with  the  plane,  or  level  of  the  wall-plate  ;  or 
it  is  the  ratio  which  arises  by  dividing  the  span  by  the 
height.  Thus,  if  it  be  asked  :  What  is  the  pitch  of  such 
a  roof?  the  answer  is,  one-quarter,  one-third,  or  half. 
When  the  pitch  is  half,  the  roof  is  a  square,  which  is  the 
highest  that  is  now  in  use,  or  that  is  necessary  in  practice. 

Plank. — All  boards  above  an  inch  thick  are  called 
planks. 

Plate. — A  horizontal  piece  of  timber  in  a  wall,  gener- 
ally flush  with  the  inside,  for  resting  the  ends  of  beams, 
joists  or  rafters,  upon  ;  and,  therefore,  denominated  floor 
or  roof  plates. 

Posts. — All  upright  or  vertical  pieces  of  timber  what- 
ever ;  as  truss-posts,  door-posts,  quarters  in  partitions,  etc. 

Brick  Posts. — Intermediate  posts  in  a  wooden  build- 
ing, framed  between  principal  posts. 

Principal  Posts. — The  corner  posts  of  a  wooden 
building. 

PuDLAIES. — Pieces  of  timber  to  serve  the  purpose  of 
hand-spikes. 

Puncheons. — Any  short  post  of  timber.  The  small 
quarterings  in  a  stud  partition,  above  the  head  of  a  door, 
are  also  called  puncheons. 

Purlins. — The  horizontal  timbers  in  the  sides  of  a  roof, 
for  supporting  the  spars  or  small  rafters. 

Quartering. — The  stud  work  of  a  partition. 

Quarters. — The  timbers  to  be  used  in  stud  partitions, 
bond  in  walls,  etc. 

Rafters. — All  the  inclined  timbers  in  the  sides  of  a 
roof ;  as  principal  rafters,  hip  rafters,  and  common  rafters  ; 
the  latter  are  called  in  most  countries,  spars. 

Rails. — The  horizontal  pieces  which  contain  the  tenons 


{Continued  011  page  71.) 


CARPENTRY. 


PLATE  33- 

Exhibits  the  plan  and  elevation  for  a  platform  stair-case. 

To  find  the  point  to  bore  for  the  first  short  baluster  on. 
the  second  step.  At  Fig.  i,  place  the  point  of  the  pitch- 
board  ;  at  B,  the  centre  of  the  newel  post,  set  up  on  the 
rise  from  C  to  A  equal  to  the  difference  in  the  heights  of 
the  newel  post  and  the  short  baluster,  say  six  inches. 
Then  the  riser  intersects  the  rail  at  the  point  required. 

To  form  the  face  mould  for  the  wreath. 

At  Fig.  3,  place  the  pitch-board,  and  draw  the  pitch  line 
C  D  ;  transfer  the  distances  from  the  plan,  Fig.  2,  for  the 
width  of  the  mould  at  the  joints.  The  elliptical  curves 
for  the  outside  and  inside  of  the  mould  are  drawn  with  a 
cord  or  string.  The  points  for  the  pins  are  found  in  the 
same  manner  as  in  plate  1,  Fig.  1. 

The  application  of  the  mould  and  bevel  drawn  at  Fig. 
3,  are  demonstrated  at  Fig.  4.  The  plank  sawed  square, 
place  the  bevel  on  the  joint,  and  draw  the  perpendicular 
line  ;  set  off  from  the  centre  of  the  plank,  each  way,  half 
the  width  and  thickness  of  the  rail.  Apply  the  mould, 
and  mark  the  piece  for  the  corners  to  be  removed  ;  the 
same  operation  is  required  for  the  opposite  side.  Tack 
the  mould  on  the  side  opposite  the  corners  to  be  removed. 
Care  should  be  taken  to  keep  the  saw  or  plane  perpen- 
dicular to  the  plane  of  the  rail  when  in  position.  Re- 
move the  surplus  wood  on  the  upper  and  lower  si'tes  of 
the  plank,  and  form  the  wreaths  required  at  Fig.  5.  The 
casing  on  second  floor  terminates  half  the  height  of  the 
riser  above  the  point  to  bore  for  the  first  baluster  <?n  the 
floor. 


/ 


TERMS  USED  IN  CARPENTRY.  71 


in  a  piece  of  framing,  in  which  the  upper  and  lower  edges 
of  the  panels  are  inserted. 

Raising  Plates  or  Top  Plates. — The  plates  on  which 
the  roof  is  raised. 

Rank-set. — The  edge  of  the  iron  of  a  plane  is  said  to 
be  rank-set  when  it  projects  considerably  below  the  sole. 

Return. — In  any  body  with  two  surfaces,  joining  each 
other  at  an  angle,  one  of  the  surfaces  is  said  to  return  in 
respect  of  the  other  ;  or,  if  standing  before  one  surfacer 
so  that  the  eye  may  be  in  a  straight  line  with  the  other, 
or  nearly  so,  this  last  is  said  to  return. 

Ridge. — The  meeting  of  the  rafters  on  the  vertical 
angle,  or  highest  part  of  a  roof. 

Risers. — The  vertical  sides  of  the  steps  of  stairs. 

Roof. — The  covering  of  a  house  ;  but  the  word  is  used 
in  carpentry  for  the  wood-work  which  supports  the  sla- 
ting or  other  covering. 

Scantling. — The  transverse  dimensions  of  a  piece  of 
timber  ;  sometimes,  also,  the  small  timbers  in  roofing  and 
flooring  are  called  scantlings. 

Scarfing. — A  mode  of  joining  two  pieces  of  timber,, 
by  bolting  or  nailing  them  transversely  together,  so  that 
the  two  appear  as  one.  The  joint  is  called  a  scarf,  and 
timbers  are  said  to  be  scarfed. 

Shaken  Stuff. — Such  timber  as  is  rent  or  split  by  the 
heat  of  the  sun,  or  by  the  fall  of  the  tree,  is  said  to  be 
shaken. 

Shingles. — Thin  pieces  of  wood  used  for  covering, 
instead  of  tiles,  etc. 

Shreadings. — A  term  not  much  used  at  present. 

Skirtings  or  Skirting  Boards. — The  narrow  boards 
around  the  margin  of  a  floor,  forming  a  plinth  for  the 
base  of  the  dado,  or  simply  a  plinth  for  the  room  itself, 
when  there  is  no  dado. 

Skirts  of  a  Roof. — The  projecture  of  the  eaves. 

Sleepers. — Pieces  of  timber  for  resting  the  ground- 
joists  of  a  floor  upon,  or  for  fixing  the  planking  to.  in  a 


(Continued  on  page  73.) 


« 


HAND  RAILING. 


PLATE  34. 

Figures  i,  2. — Represent  the  plans  and  elevation  of  a 
continued  hand-rail.  At  the  landing  of  the  first  flight, 
also  at  the  starting  of  the  second  flight,  care  should  be 
taken,  in  forming  the  wreath,  to  rise  from  the  point  A  to  B 
at  the  landing,  and  from  C  to  D  at  the  starting,  equal 
to  half  the  height  of  the  riser.  The  level  rail  commences 
and  terminates  at  the  joints  ;  consequently  one  wreath 
only  will  be  required  for  each  of  the  semi-circular  parts  of 
the  hand-rail.  To  draw  the  face  mould  for  the  wreaths, 
proceed  in  the  same  manner  as  described  in  the  preceding 
plate. 

The  operation  of  drawing  the  mould  for  the  wreaths  is 
precisely  the  same  for  large  or  small  cylinders ;  but,  in 
large  openings,  it  is  necessary  to  place  the  risers  in  the 
cylinders.  The  rules  for  finding  their  exact  position  for 
platform  stairs  are  demonstrated  at  Fig.  3  and  Fig.  4,  as 
follows:  At  Fig.  4,  from  the  point  B,  draw  the  pitch-lines 
B  D  and  B  E ;  set  off,  above  and  below,  the  thickness  of 
the  rail.  Draw  G  F,  at  right  angles  to  the  plan,  equal  to 
the  riser.  At  Fig.  3,  draw  the  plan  of  the  rail  any  size, 
say  twelve  inches;  produce  the  riser  F  G  from  Fig.  4  to 
H,  Fig.  3,  cutting  the  cylinder  at  the  points  required. 
The  same  rule  may  be  applied  at  the  landing  and  starting 
of  straight  flights,  by  extending  the  radius  from  S  to  L, 
and  placing  the  rise  the  same  distance  from  the  centre  of 
the  rail  as  demonstrated  by  the  dotted  line  and  curves  at 
Fig.  1.  The  width  of  the  rail  determines  the  thickness  of 
the  plank  required  for  the  wreaths. 


Plate  34  n 


Sca/e/ i  foot. 


TERMS  USED  IN  CARPENTRY.  73 


bad  foundation.  The  term  formerly  applied  to  the  valley 
rafters  of  a  roof. 

Spars. — A  term  by  which  the  common  rafters  of  a  roof 
are  best  known  in  almost  every  provincial  town  in  Great 
Britain ;  though,  generally,  called  in  London  common 
rafters  in  order  to  distinguish  them  from  the  principal 
rafters. 

Staff. — A  piece  of  wood  fixed  to  the  external  angle  of 
the  two  upright  sides  of  a  wall,  for  floating  the  plaster  to, 
and  for  defending  the  angle  against  accidents. 

Stiles  of  a  Door  are  the  vertical  parts  of  the  framing 
at  the  edges  of  the  door. 

Struts. — Pieces  of  timber  which  support  the  rafters 
and  which  are  supported  by  the  truss-post. 

Summer. — A  large  beam  in  a  building,  either  disposed 
in  an  outside  wall,  or  in  the  middle  of  an  apartment,  par- 
allel to  such  wall.  When  a  summer  is  placed  under  a 
superincumbent  part  of  an  outside  wall,  it  is  called  a 
firessummer,  as  it  comes  in  abreast  with  the  front  of  the 
building. 

Surbase. — The  upper  base  of  a  room,  or  rather  the 
cornice  of  the  pedestal  of  the  room,  which  serves  to  finish 
the  dado,  and  to  secure  the  plaster  against  accidents 
from  the  back  of  chairs  and  other  furniture  on  the  same 
level. 

Taper. —  The  form  of  a  piece  of  wood  which  arises 
from  one  end  of  a  piece  being  narrower  than  the  other. 
TENON. — See  Mortise. 

Tie. — A  piece  of  timber,  placed  in  any  position,  and 
acting  as  a  string  or  tie,  to  keep  two  things  together 
which  have  a  tendency  to  a  more  remote  distance  from 
each  other. 

Transom  Windows. — Those  windows  which  have  hori- 
zontal mullions. 

Trimmers. — Joists  into  which  other  joists  are  framed. 

Trimming  Joists. — The  two  joists  into  which  a  trim- 
mer is  framed. 


Continued  on  page  75. 


74 


CARPENTRY. 


PLATE  35. 

Exhibits  the  plan  for  groin  arches  designed  for  stone  or  brick 
materials. 

To  form  the  diagonal  ribs  resting  on  the  piers  C,  D,  E, 
F.  At  Fig.  i,  describe  the  semi-circle  A  G  H  ;  divide  the 
arc  A  G  into  any  number  of  equal  parts  ;  from  the  points, 
draw  lines  at  right  angles  to  A  H  intersecting  the  diago- 
nal line  I  K  ;  from  the  points  of  intersection,  draw  lines  at 
right  angles  to  I  K  and  L  M,  indefinitely.  Transfer  the 
distances  n,  22,  etc.  from  A  H  ;  through  the  points  trace 
the  elliptical  curves  required. 

Figure  2. — Exhibits  the  elliptic  curve  L  M  drawn  with 
a  cord  or  string. 


TERMS  USED  IN  CARPENTRY.  75 


Truncated  Roof. — A  roof  with  a  flat  on  the  top. 

Truss. — A  frame  constructed  of  several  pieces  of  tim- 
ber, and  divided  into  two  or  more  triangles  by  oblique 
pieces,  in  order  to  prevent  the  possibility  of  its  revolving 
round  any  of  the  angles  of  the  frame. 

Trussed  Roof. — A  roof  so  constructed  within  the  ex- 
terior triangular  frame,  as  to  support  the  principal  rafters 
and  the  tie-beam  at  certain  given  points. 

Truss-Post. — Any  of  the  posts  of  a  trussed  roof,  as  a 
king-post,  queen-post,  or  side-post,  or  posts  into  which  the 
braces  are  formed  in  a  trussed  partition, 

Trussells. — Four-legged  stools  for  ripping  and  cross- 
cutting  timber  upon. 

Tusk. — The  beveled  upper  shoulder  of  a  tenon,  made 
in  order  to  give  strength  to  the  tenon. 

Uphers. — Fir  poles,  from  twenty  to  forty  feet  long,  and 
from  four  to  seven  inches  in  diameter,  commonly  hewn, 
on  the  sides,  so  as  not  to  reduce  the  wane  entirely.  When 
slit  they  are  frequently  employed  in  slight  roofs,  but 
mostly  used  whole  for  scaffolding  and  ladders. 

Valley  Rafter. — That  rafter  which  is  disposed  in  the 
internal  angle  of  a  roof. 

Wall  Plates. — The  joint-plates  and  raising  plates. 

Web  of  an  Iron. — The  board  part  of  it  which  comes 
to  the  sole  of  the  plane. 


7(5 


CARPENTRY. 


PLATE  36. 

Exhibits  a  Geometrical  demonstration  of  squaring  the  circle. 

To  find  the  side  of  a  square  equal  in  area  to  the  area  of 
the  circle.  From  the  point  A  as  centre,  with  A  D  as 
radius,  describe  the  circle.  From  the  point  D  as  centre, 
describe  the  arc  A  B.  From  the  point  B,  draw  B  C  at 
right  angles  to  D  T.  From  the  point  B  as  centre,  with 
B  C  as  radius,  describe  an  arc  cutting  the  circle  at  F. 
From  the  point  F,  parallel  to  N  D,  draw  a  line  to  inter- 
sect the  diameter  D  T  at  J  ;  from  the  point  J,  draw  J  S 
at  right  angles  to  D  T.    Join  S  T,  the  side  required 

To  find  the  side  of  a  square  whose  sides  shall  equal  the 
circumference  of  the  circle.  Produce  the  line  J  F  to  L: 
then  T  L  equals  %  of  the  circumference,  and  \\  of  the 
diameter;  the  side  required. 

To  find  the  side  of  a  cube,  the  content  of  which  shall 
equal  the  content  of  a  globe  or  ball.  From  the  point  N 
as  centre,  with  N  P  as  radius,  describe  an  arc  cutting  the 
circle  at  H.    Join  H  T,  the  side  required. 

{For  Rules  and  Examples  see  pp.  68  and  69.) 


MATHEMATICAL  DEMONSTRATION 

OF 

SQUARING  THE  CIRCLE. 

RULES. 

1.  Eleven-fourteenths  (JJ)  of  the  diameter  equals  one- 
fourth  (i^)  of  the  circumference. 

2.  To  find  the  area  of  the  circle.  Multiply  the  diameter 
by  the  radius,  and  divide  the  product  by  7  ;  the  quotient 
multiplied  by  1 1  gives  the  area  of  the  circle. 

EXAMPLE. 

Diameter  28X14=392-^-7=56X1 1=616,  area  of  circle. 

3.  To  find  the  side  of  a  square  the  area  of  which  shall  be 
equal  to  the  area  of  the  circle.  Divide  the  diameter  by  14, 
multiply  the  quotient  by  11,  add  to  the  product  one-tenth 
(i)  of  the  diameter,  and  annex  the  first  figure  in  the  quo. 
tient. 

EXAMPLE. 

Diameter  28^-14=2. 

Product     2X11=22.         one-fourth  (%)  of  the  circum. 

2.82  :    one-tenth  do)  of  the  diameter 

Side  of   square  \   with  quotient  annexed. 

equal   in  area  to  >  24.82 
area  of  circle.  ) 

Proof:  28X22=616  ;  the  square  root  of  which  is 
24.8193.  Add  the  quotient  when  it  consists  of  two  or 
more  figures. 

EXAMPLE. 

Diameter  224-^-14=16 

Product  1 6Xn=  176     One-fourth  (%)  of  the  circum. 

22.4  One-tenth  do)  of  the  diam. 

Side  of  square  )        16  Quotient  added. 

equal  in  area   to  >  

area  of  circle.       )  198.56 


78 


MATHEMATICAL  DEMONSTRATION. 


Proof :  224^176=39424  the  square  root  of  which  is 
198.5547. 

4.  Eleven-fourteenths  (}})  of  the  area  of  the  circle  equals 
the  area  of  a  square  whose  sides  are  equal  to  the  circum- 
ference. 

5.  Seven-elevenths  (J)  of  the  area  of  the  circle  equals  the 
area  of  an  inscribed  square. 

6.  One-fourth  {%)  of  the  circumference  multiplied  by 
nine  (9),  the  product  divided  by  ten  (10),  equals  the  side  of 
an  inscribed  squaie,  nearly. 

7.  To  fi?id  the  diameter  when  the  circumference  is  given. 
Multiply  by  seven  (7)  and  divide  by  twenty-two  (22.) 

8.  To  find  the  diameter  when  the  area  of  the  circle  is  given. 
Divide  by  fourteen  (14),  and  multiply  the  quotient  by 
eleven  (11);  the  square  root  of  the  product  equals  one- 
fourth  {%)  of  the  circumference  ;  to  find  the  diameter 
proceed  as  in  Rule  7. 

These  rules  give  the  exact  circumference  of  the  circle, 
where  the  diameters  are  1,  2,  3,4,  etc.,  multiplied  by  seven 
(7),  with  as  much  certainty  as  you  can  find  the  root  of  a 
rational  number,  and  will  be  found  very  useful  to  work- 
men. 


4  » 


